Bulletin  No.  15,  New  Series.  . 

U.  S.  DEPARTMENT  OF  AGRICULTURE. 

DIVISION  OF  ENTOMOLOGY. 


THE  CHINCH  BUG: 


ITS  PROBABLE  ORIGIN  AND  DIFFUSION,  ITS  HABITS  AND 
DEVELOPMENT,  NATURAL  CHECKS  AND  REMEDIAL 
AND  PREVENTIVE  MEASURES, 

WITH 

MENTION  OF  THE  HABITS  OF  AN  ALLIED  EUROPEAN  SPECIES. 


PREPARED  UNDER  THE  DIRECTION  OF  THE  ENTOMOLOGIST, 

By  F.  M.  WEBSTER, 

Entomologist  of  the  Ohio  Agricultural  Experiment  Station. 


WASHINGTON: 

GOVERNMENT   PRINTING  OFFICE. 
1898. 


DIVISION  OF  ENTOMOLOGY. 


Entomologist :  L.  O.  Howard. 

Assist.  Entomologists :  C.  L.  Marlatt,  Th.  Pergande,  F.  H.  Chittenden,  Frank  Benton. 
Investigators :  E.  A.  Schwarz,  H.  G.  Hubhard,  D.  W.  Coqnillett. 

Assistants:  R.  S.  Clifton,  Nathan  Banks,  F.  C.  Pratt,  Aug.  Busek,  Otto  Heidemann. 
Artist:  Miss  L.  Sullivan. 


Bulletin  No.  15,  New  Series. 

U.  S.  DEPARTMENT  OF  AGRICULTURE. 

DIVISION  OF  ENTOMOLOGY. 


THE  CHINCH  BUG: 

ITS  PROBABLE  ORIGIN  AND  DIFFUSION,  ITS  HABITS  AND 
DEVELOPMENT,  NATURAL  CHECKS  AND  REMEDIAL 
AND  PREVENTIVE  MEASURES, 

WITH 

MENTION  OF  THE  HABITS  OF  AN  ALLIED  EUROPEAN  SPECIES. 

PREPARED  UNDER  THE  DIRECTION  OF  THE  ENTOMOLOGIST, 

By  F.  M.  WEBSTER, 

Entomologist  of  the  Ohio  Agricultural  Experiment  Station. 


WASHINGTON: 

GOVERNMENT   PRINTING  OFFICE. 

1898. 


LETTER  OF  TRANSMITTAL. 


IT.  S.  Department  of  Agriculture, 

Division  of  Entomology, 
Washington,  D.  C,  August  25,  1898. 
Sir  :  I  have  the  honor  to  transmit,  for  publication  as  Bulletin  No.  15, 
new  series,  of  this  office,  a  manuscript  upon  the  chinch  bug,  which  has 
been  prepared  at  your  direction  and  under  my  supervision  by  P.  M. 
Webster,  the  entomologist  of  the  Ohio  Agricultural  Experiment  Sta- 
tion. This  insect  was  the  subject  of  a  bulletin  prepared  by  myself  and 
published  as  No.  17  of  the  old  series  of  this  Division  in  1885.  Since 
that  time,  however,  many  new  facts  have  been  learned  concerning  the 
life  history  and  distribution  of  the  species,  and  the  whole  subject  of 
the  practical  handling  of  its  diseases  has  been  elaborated.  The  chinch 
bug  is  one  of  the  half  dozen  most  destructive  insects  with  which  the 
American  farmer  has  to  contend,  and  requests  for  information  about  it 
are  constantly  received  by  the  Department.  It  is  therefore  necessary 
that  the  Department  should  have  for  distribution  a  full  and  up-to-date 
bulletin  such  as  this  aims  to  be.  Professor  Webster,  by  virtue  of  his 
familiarity  with  this  insect,  gained  through  long  and  careful  study  in 
advantageous  localities,  was  admirably  fitted  for  the  work,  which,  it 
seems  to  the  writer,  has  been  well  done. 

Respectfully,  L.  O.  Howard, 

Entomologist. 

Hon.  James  Wilson, 

Secretary  of  Agr  iculture. 

3 


CONTENTS. 


Page. 


Distribution  .'   9 

Hibernation   10 

Spring,  summer,  and  autumn  migrations   17 

Oviposition   18 

Egg  period  and  number  of  eggs  deposited  by  each  female   19 

Descriptions  of  the  different  stages  of  development   19 

Development  and  habits  of  the  young    21 

Number  of  annual  generations   23 

Gregarious  habits  of  the  chinch  bug   26 

Food  plants   27 

Losses  caused  by  chinch  bugs     29 

Natural  checks   31 

Influence  of  precipitation  on  the  chinch  bug   31 

Influence  of  temperature  on  the  chinch  bug   38 

.  Natural  enemies   39 

Parasitic  fungi   39 

Fungous  enemies  of  the  chinch  bug  determined   41 

Field  and  laboratory  experiments  in  Indiana   42 

First  field  applications  of  fungous  enemies  of  the  chinch  bug   45 

The  work  of  Professor  Snow  in  Kansas   46 

Other  insects  attacked  by  Sporotriehium  globuKferum   47 

First  artificial  cultivations  of  Sporotrichium  globti lifer um   48 

Results  of  field  applications  in  Ohio   48 

Meteorological  influences  favoring  development  of  fungous  enemies  of 

the  chinch  bug   50 

A  bacterial  enemy  of  the  chinch  bug   51 

The  practical  utility  of  fungous  and  bacterial  enemies  in  fighting  the 

chinch  bug   51 

The  quail   52 

Other  bird  enemies  of  the  chinch  bug   53 

The  frog   53 

Invertebrate  enemies  of  the  chinch  bug   53 

Remedial  and  preventive  measures   54 

Destruction  of  chinch  bugs  while  in  hibernation   54 

Sowing  decoy  plots  of  attractive  grains  or  grasses  in  early  spring   55 

Difficulty  of  reaching  chinch  bugs  in  meadows   56 

Watchfulness  necessary  during  protracted  periods  of  drouth   57 

Utility  of  kerosene  in  fighting  chinch  bugs   57 

Utility  of  deeply  plowed  furrows  supplemented  by  the  use  of  kerosene 

emulsion   58 

The  ridge  and  coal  tar  method   59 

Other  barrier  methods   60 

Necessity  for  preventing  chinch  bugs  from  becoming  established  in  fields 

of  wheat  and  grass   61 

Summary  of  remedial  and  preventive  measures   63 

5 


G  CONTENTS. 

Page. 

Insects  that  are  mistaken  for  chinch  bugs   64 

Probable  origin  and  diffusion  of  the  chinch  bug   66 

Indications  of  a  probable  distant  origin  and  later  diffusion   67 

Tnique  appearance  and  gregarious  habit   68 

Occurrence  of  the  long  and  short  winged  forms  and  their  distribution   69 

Relation  of  the  inland  and  seacoast  short-winged  forms   71 

Probable  course  of  diffusion   71 

Habits  of  the  European  species,  Blissus  dories  Eerr   75 

Previous  ideas  on  the  diffusion  of  the  chinch  bug   78 

Reasons  for  the  present  theory  of  diffusion   80 


ILLUSTRATIONS. 


Page. 

Fig.  1. — Map  of  North  America  showing  areas  infested  by  chinch  bug   11 

2.  — Immature  stages  of  chinch  bug   19 

3.  — Blissus  leucopterus — adults  of  long  and  short  winged  forms   20 

4.  — Blissus  leucopterus — adults  of  short-winged  seashore  form   20 

5.  — Corn  plant  infested  with  chinch  bugs   28 

6.  — Map  showing  areas  in  the  United  States  over  which  the  chinch  bug 

occurs  in  most  destructive  numbers   31 

7.  — Map  showing  distribution  of  chinch  bug  in  Ohio  in  1896   32 

8.  — Map  showing  distribution  of  chinch  bug  in  Ohio  in  1897   33 

9.  — Map  showing  distribution  of  chinch  bug  in  Ohio  in  1894   31 

10.  — Map  showing  distribution  of  chinch  bug  in  Ohio  in  1895  and  amount 

of  precipitation  over  the  State  during  May,  1895    35 

11.  — Triphleps  insidiosus  Say   53 

12.  — Mihjas  cinctus  Fab   54 

13.  — Xysius  angustatus   04 

14.  — Piesma  cinerea   65 

15.  — Corimelcma  pu  licaria   65 

16.  — Brachyrhynchus  yranulatus — larva,  pupa,  and  adults   65 

17.  — Map  showing  probable  course  of  diffusion  of  chinch  bug  over  North 

America   72 

18.  — Blissus  doriw — immature  stages   76 

19.  — Blissus  dorice — adults   76 


7 


Digitized  by  the  Internet  Archive 
in  2013 


http://archive.org/details/chprobOOunit 


THE  CHINCH  BUG. 


Few  insects,  and  certainly  no  other  species  of  the  natural  order  to 
which  it  belongs,  have  caused  such  enormous  pecuniary  losses  as  has 
the  chinch  bug,  Blissus  leucopterus  Say.  No  other  insect,  native  to  the 
Western  Hemisphere,  has  spread  its  devastating  hordes  over  a  wider 
area  of  country  with  more  fatal  effects  to  the  staple  grains  of  North 
America  than  has  this  one.  But  for  the  extreme  susceptibility  of  the 
very  young  to  destruction  by  drenching  rains  and  to  the  less  though 
not  insignificant  destructiveness  during  rainy  seasons  of  the  parasitic 
fungus,  Sporotrichium  globuliferum  Speg.,on  both  the  adults  and  young, 
the  practice  of  raising  grain  year  after  year  on  the  same  areas,  as  fol- 
lowed in  the  United  States,  would  be  altogether  unprofitable.  Some 
of  this  insect's  own  habits,  also  emphasizing  as  they  do  the  effects  of 
meteorological  conditions,  are  the  most  potent  influences  that  serve  to 
hold  it  within  bounds,  by  giving  its  tendency  to  excessive  increase  a 
decidedly  spasmodic  character. 

DISTRIBUTION. 

The  genus  Blissus  is  widely  distributed  over  the  world,  occurring  in 
South  Africa,  Abyssinia,  southern  Europe,  northward  at  least  to  the 
sand  dunes  of  central  and  northern  Hungary,  and  in  the  Western 
Hemisphere  from  Panama  and  the  Island  of  St.  Vincent  northward  to 
middle  California  on  the  Pacific  coast  and  Cape  Breton  on  the  Atlantic. 
When  we  come  to  understand  that  the  hemiptera  of  the  world  are  far 
from  being  well  known,  and  the  faunas  of  South  America  and  central 
Africa  have  as  yet  hardly  been  studied  at  all,  we  may  well  presume 
that  future  studies  of  the  hemipterous  insects  of  these  countries  may 
fill  in  some  of  the  wide  stretches  of  country  separating  the  different 
areas  now  known  to  be  inhabited  by  the  several  species  of  this  genus. 

At  present  in  the  Old  World  it  may  be  said  to  occur  in  the  Ethiopian, 
Oriental,  Sonoran,  and  Holarctic  life  zones,  while  in  the  New  World 
it  ranges  from  the  Neotropical  at  Panama  and  St.  Vincent,  through  the 
Sonoran  and  past  the  borders  of  the  Holarctic  in  British  America. 

Our  American  species,  Blissus  leucopterus  Say,  the  only  one  at  present 
known  in  the  Western  Hemisphere,  has  been  recorded  from  St.  Vincent 
and  Grenada,  West  Indies,  by  Uhler ;  Cuba,  by  Stal ;  Volcan  de  Chiriqui, 
Bugaba,  and  San  Feliz,  Panama,  by  Champion;  San  Geronimo,  Paso 
Antonio,  Pauzos,  Champerico,  and  Rio  Naranjo,  Guatemala,  by  Cham- 
pion; Lower  Purissima,  Lower  California,  by  Uhler;  Alameda,  Cal., 

9 


10 


THE  CHINCH  BUG. 


by  Koebele;  and  in  the  vicinity  of  San  Francisco,  Cal.,  by  both  Uhler 
and  Koebele;  Orizaba,  Mexico,  by  H.  H.  Smith;  Tamaulipas,  Mexico, 
by  Uhler;  Mesilla  Park,  N.  Mex.,  by  Oockerell;  Florida,  by  Sehwarz 
and  Dr.  J.  0.  Neal;  Sydney,  Cape  Breton,  by  W.  H.  Harrington;  Mus- 
koka,  Ontario,  Canada,  by  E.  P.  Van  Duzee;  and  Winnipeg,  Manitoba, 
where  a  single  specimen  was  collected  by  Dr.  James  Fletcher  and 
given  by  him  to  Mr.  Harrington,  to  whom  1  am  indebted  for  informa- 
tion regarding  its  occurrence.  Inland,  in  the  United  States,  it  may  be 
said  to  be  generally  distributed  from  Texas  to  Manitoba  and  eastward 
to  the  Atlantic  coast,  along  which  it  is  known  to  occur  almost  con- 
tinuously from  Cape  Breton  to  Cape  Florida.  It  is  also  very  probable 
that  its  occurrence  along  the  Pacific  coast  is  much  more  extended 
than  is  at  present  known,  as  it  has  not  been  searched  for  to  any  extent 
in  that  region.    (See  map,  fig.  1.) 

HIBERNATION. 

The  chinch  bug  hibernates  in  the  adult  stage,  and  though  there  may 
be  occasional  exceptions,  especially  in  the  South,  it  has  yet  to  be 
observed  in  very  early  spring  in  any  other  than  the  adult  stage,  at  least 
in  any  locality  north  of  Mexico.  I  have  observed  pupa?  in  central 
Illinois  apparently  in  hibernation  in  company  with  adults  on  November 
11,  but  there  is  no  proof  that  these  survived  the  winter.  In  Tensas 
Parish,  La.,  adults  were  abroad  in  considerable  numbers  during  March, 
1887,  yet  there  was  no  indication  of  any  young  having  wintered  over. 
The  adults  were  pairing  and  seemingly  engaged  in  oviposition,  pre- 
cisely as  is  to  be  observed  in  the  Northern  States  during  May  and  June. 
I  did  not  observe  any  young,  as  I  most  certainly  should  have  done  had 
they  occurred,  as  my  observations  were  made  in  fields  of  young  corn, 
where,  had  the  young  bugs  been  present  even  in  very  limited  numbers, 
they  would  certainly  not  have  escaped  my  rigid  searching  under  and 
about  the  bases  of  the  leaves  of  the  young  corn  plants. 

Dr.  Howard*  quotes  Prof.  G.  F.  Atkinson,  at  that  time  of  Chapel 
Hill,  N.  C,  as  having  observed  half  grown  chinch  bugs  on  crab  grass, 
about  the  1st  of  October.  The  same  authority  also  quotes  Dr.  Biley 
to  the  effect  that  many  of  the  chinch  bugs  pair  in  the  fall  preparatory 
to  seeking  winter  quarters,  and  also  cites  the  fact  that  Mr.  James  O. 
Alwood  observed  them  pairing  in  a  field  of  uncut  pearl  millet,  October 
27,  1887,  on  the  grounds  of  the  Ohio  Agricultural  Experiment  Station, 
then  at  Columbus,  Ohio.  Dr.  Cyrus  Thomas.f  in  speaking  of  the  pos- 
sibilities of  an  occasional  third  brood  in  southern  Illinois  and  Ken- 
tucky, states  that  there  were  some  evidences  of  this,  but  not  sufficient 
to  justify  him  in  asserting  it  as  a  fact  or  to  satisfy  him  of  its  correct- 
ness. 

*The  Chinch  Bug,  by  L.  O.  Howard;  Report  of  the  Commissioner  of  Agriculture 
for  the  year  1887,  pp.  51-88. 

t  Bulletin  No.  5,  U.  S.  Entomological  Commission,  p.  13. 


HIBERNATION. 


11 


Fig.  1.— Map  of  North  America  showing  areas  infested  hy  chinch  hug  (original). 


12 


THE  CHINCH  BUG. 


It  therefore  seems  probable  that  no  young  are  produced  as  a  result 
of  the  late  pairing,  at  least  until  spring,  and  it  has  yet  to  be  shown 
that  the  late  appearing  larvae  do  not  mature  before  the  hibernating 
season  sets  in,  or  else  die  during  the  winter.  When  we  come  to  con- 
sider the  extreme  susceptibility  of  the  newly  hatched  chinch  bug  to 
wet  weather,  it  will  be  apparent  that,  as  we  approach  the  tropics,  the 
wet  and  dry  seasons  would  exert  a  powerful  influence  in  regulating 
the  breeding  seasons,  as  those  individuals  that  hatched  before  the 
close  of  the  rainy  season  would  be,  largely,  at  least,  contiuuaily  elimi- 
nated, while  those  that  hatched  so  late  as  to  be  caught  in  the  com- 
mencement of  the  rainy  season  would  also  be  to  an  equally  great 
extent  destroyed,  and  thus,  by  continually  restricting  the  breeding 
period  to  certain  months,  establish  a  fixed  law  that  would  be  adhered 
to  even  under  the  somewhat  different  conditions  which  occur  farther  to 
the  northward.  Unfortunately,  I  do  not  have  the  date  or  dates  on 
which  the  young  were  observed  by  Mr.  Champion,  on  Volcan  de  Chiri- 
qui,  in  Panama,  but  it  seems  very  probable  that  they  were  found  during 
or  near  the  dry  season. 

In  an  article  on  the  hibernation  of  the  chinch  bug,  Mr.  0.  L.  Marlatt* 
calls  particular  attention  to  the  fact  that  in  Kansas  the  chinch  bug  in 
autumn  seeks  the  dense  stools  of  some  of  the  wild  grasses  in  which  to 
hibernate,  and  to  such  an  extent  did  this  occur  that  it  was  suggested 
as  probably  the  normal  hibernatiug  habit  of  the  species. 

Before  entering  into  a  discussion  of  this  matter,  it  will  be  well  to 
present  two  communications  received  from  the  late  Dr.  J.  C.  'Neal,  at  that 
time  of  Stillwater,  Okla.  As  he  was  located  in  a  section  of  the  country 
where,  in  many  cases,  civilization  had  not  influenced  to  such  a  marked 
degree  the  natural  insect  fauna,  I  applied  to  him  to  secure  some  exact 
information  in  regard  to  the  chinch  bug  under  such  conditions.  Our 
correspondence,  however,  was  terminated  suddenly  by  his  death.  The 
two  letters  here  given  are  among  the  last  he  ever  penned.  They  are 
of  a  somewhat  general  nature,  and  I  shall  refer  to  them  later  in  this 
discussion. 

Oklahoma  Agricultural  and  Mechanical  College, 

Stillwater,  Ol  la.,  October  31, 1895. 
My  Dear  Sir:  Yours  of  the  28tli  just  received.  Last  year  was  the  first  wheat 
year  in  most  of  the  new  additions  to  this  Territory,  and  from  all  sections  the  cry  was 
for  infection,  as  "the  hugs  are  ruining  us."  I  received  letters  from  every  county  in 
the  strip  and  in  the  western  sections.  The  most  damage  was  done  in  the  extreme 
southern  range  of  the  counties,  and  near  Okarche  (see  map,  fig.  6)  the  damage 
was  excessive.  I  do  not  think  there  is  a  single  acre  in  this,  or  Indian  Territory  that 
is  not  saturated,  so  to  speak,  with  the  chinch  hug.  You  may  put  this  whole  area  down 
as  within  the  infested  boundary  line.  My  belief  is  that  the  increase  of  country  roads, 
the  decrease  of  March  fires,  the  shiftless  habits  of  the  vast  majority  of  our  farmers 
in  allowing  volunteer  wheat  and  oats  to  grow,  and  wheat  lands  to  remain  fallow, 
and  the  planting  of  new  and  better  grass  crops  than  the  tough  blue-stem,  are  direct 
causes  of  what  I  believe  a  decided  increase  of  this  insect  in  Oklahoma  during  the 

"  Insect  Life,  Vol.  VII,  pp.  232-234,  1894. 


HIBERNATION. 


13 


last  five  years.  It  would  be  amusing  if  it  were  not  so  pathetic,  to  read  the  many 
letters  I  get,  something  in  thiswise:  "I  planted  wheat  on  sod  land,  the  chinch  bugs 
destroyed  it  so  badly  that  in  February  I  plowed  it  up  and  sowed  oats,  this,  too 
went  the  same  way;  I  then  planted  corn,  and  when  it  was  a  foot  high  the  little 
bugs  came  by  the  millions  and  destroyed  that;  I  then  planted  the  land  to  Kafir  corn, 
and  that  will  be  ruined  if  you  can  not  help  me."  What  could  I  do  for  such  a  man? 
Had  the  bugs  laid  out  a  programme  for  their  daily  sustenance,  no  better  commissary- 
general  could  have  been  obtained  for  them  than  he  was,  and  I  had  to  write  him  that 
his  plan  was  the  worst  one  possible  for  him,  and  the  best  for  the  bugs,  and  that  the 
only  suggestion  I  could  make,  from  the  bugs  standpoint  and  for  their  benefit,  would 
be  to  plant  wheat  again  so  that  they  could  have  something  for  the  coming  winter's 
food.  In  his  case  it  was  a  series  of  fatal  mistakes  from  ignorance  of  the  habits  of 
the  bugs. 

Another  thing  which  I  believe  adds  materially  to  the  increase  of  these  pests  is  the 
complete  destruction  of  the  prairie  chickens,  the  decimation  of  partridges,  and  the 
thinning  out  of  all  kinds  of  smaller  birds,  such  as  the  cow  blackbirds,  bank  spar- 
rows, martins,  larks,  and  other  prairie  birds.  This  section  is  full  of  reckless  boys 
and  men  who  kill  everything  that  flies,  good,  bad  and  indifferent,  "for  fun." 

Some  years  ago  I  was  out  on  the  Cherokee  Strip,  miles  away  from  human  habita- 
tion, and  saw  some  of  the  small  birds — larks  and  killdees — busily  picking  in  the  young 
grass,  in  early  spring,  and  upon  examination  found  these  places  swarming  with 
chinch  bugs  sucking  the  juices  of  the  blue-stem  grass. 

Almost  any  time  in  the  winter  when  the  weather  is  warm  one  can  find  chinch  bugs, 
and  I  have  witnessed  two  "flights"  of  these  insects  and  determined  them.  I  should 
be  glad  to  answer  any  more  specific  questions  at  any  time. 

With  regards,  I  remain,  J.  C.  Neal. 

The  second  letter  is  a  short  note  in  reply  to  my  question  regarding 
the  grasses  fed  upon  by  the  chinch  bug,  their  hibernating  habits  and 
developments. 

Stillwater,  Okla.,  November  20,  1895. 

Dear  Professor  Webster  :  In  reply  to  your  postal,  I  would  say  that  I  do  not 
know,  but  will  at  once  make  observations  and  report  at  my  earliest  chance. 

My  belief  is  that  the  bugs  attack  all  the  grass  family  except  the  Cenchrus,  and 
that  only  is  exempt  on  account  of  its  bitter  taste,  which  effectually  shields  it  from 
insects,  as  far  as  I  have  seen,  both  in  this  section  and  in  Florida. 

I  will  take  the  matter  in  hand  at  as  early  a  date  as  possible  and  write  you  progress 
and  results. 

Very  respectfully,  J.  C.  Neal. 

It  is  reasonable  to  infer  from  these  letters  that  the  chinch  bug  win- 
tered over  about  the  stools  of  grass,  and  that  the  birds  were  observed 
to  attack  them  there  in  early  spring,  as  the  statement  is  made  that 
later,  when  the  young  corn  was  a  foot  high,  the  little  bugs  came  by  the 
million.  This  condition  of  affairs  may  be  considered  in  connection  with 
the  statements  of  Dr.  Asa  Fitch,*  regarding  his  observations  in  Illinois 
in  the  autumn  of  1854,  when  in  passing  over  the  northern  part  of  the 
State  he  found  the  ground  in  some  places,  in  the  midst  of  extensive 
prairies,  covered  and  swarming  with  chinch  bugs,  reminding  him,  as 
he  says,  k'of  the  appearance  presented  on  parting  the  hair  on  a  calf 
tbat  has  been  poorly  wintered,  where  the  skin  is  found  literally  alive 
with  vermin."    Farther  along  in  his  report  (p.  290)  he  states  that  "so 


*  Second  Report  on  Noxious,  Beneficial,  and  Other  Insects  of  New  York,  p.  283. 


14 


THE  CHINCH  BCG. 


late  as  the  forepart  of  October  I  met  several  of  these  insects  in  the 
pupa  state,  and  some  of  these  I  do  not  doubt  would  pass  the  winter  in 
that  state,  and  therefore  would  not  deposit  their  eggs  until  the  follow- 
ing spring."  That  he  did  not  find  these  pupre  in  New  York  is  shown 
by  his  statement  on  page  1287,  of  the  same  report,  to  the  effect  that  he 
had  met  with  but  three  specimens  in  New  York,  occurring  on  willows 
in  the  spring  of  1847  aud  May  12,  1851."  As  shown  farther  on  in  this 
bulletin,  there  is  no  proof  that  these  pupae  did  not  develop  to  adults 
before  winter,  or  die  before  spring,  and  the  conditions  indicated  would 
almost  presuppose  that  hibernation  would  take  place  on  the  prairies 
where  the  insects  were  observed  by  Dr.  Fitch.  From  personal  recol- 
lection I  know  that  that  section  of  the  country  was,  at  the  time  men- 
tioned, but  thinly  populated,  and  there  were  still  very  extensive  tracts 
of  the  original  prairie  grasses  miles  distant  from  woodlands. 

In  an  interesting  note  by  Mr.  E.  A.  Schwarz  #  on  the  hibernation  of 
the  chinch  bug,  in  discussing  Mr.  Marlatt's  paper,  previously  mentioned, 
attention  is  called  to  the  fact  that  the  hibernation  of  the  chinch  bug 
had  been  observed  by  him,  in  its  maritime  home,  in  the  vicinity  of 
Fortress  Monroe,  Va.,  which  locality  he  had  been  in  the  habit  of 
visiting  for  a  number  of  years,  during  the  first  warm  days  of  spring. 
The  maritime  flora  and  fauna  are  here  late  to  awake,  and  most  insects 
peculiar  to  the  seacoast  can  still  be  found  in  their  winter  quarters  by 
the  end  of  April.  By  pulling  up  any  good- sized  stool  of  grass  and 
beating  it  out  on  the  smooth  surface  of  the  sand  or  over  a  cloth  a 
multitude  of  various  insects  are  sure  to  be  found,  and  among  them 
always  plenty  of  chinch  bugs.  These  stools  of  grass  not  only  serve  as 
winter  quarters,  but  in  summer  the  chinch  bugs  crawl  into  them  to 
protect  themselves  during  the  daytime  from  the  fierce  rays  of  the  sun. 

In  the  timothy  meadows  of  northeastern  Ohio  a  similar  phenomenon 
may  be  observed,  and  I  have  witnessed  cases  where  the  chinch  bugs 
had  commenced  their  operations  along  one  side  and  worked  part  way 
across  the  field,  killing  the  timothy  as  they  advanced,  and  continuing 
their  depredations  the  following  year  precisely  where  they  suspended 
work  the  autumn  before,  the  long-winged  individuals  only  migrating 
in  the  intervening  time.  Thus  the  forms  infesting  this  region  have 
deteriorated  from  their  maritime  progenitors,  and  the  short-winged 
individuals  at  least  are  more  primitive  than  the  more  highly  developed 
and  specialized  long-winged  form  inhabiting  the  country  to  the  west. 
I  believe  that  a  careful  survey  of  the  timothy  meadows  of  New  York 
and  New  England,  and  perhaps  a  more  laborious  study  of  those  of 
Ontario,  Canada,  and  of  Michigan,  would  reveal  a  similar  condition, 
though  possibly  to  a  less  degree  than  at  present  exists  in  northeastern 
Ohio.  Also  if  these  same  timothy  meadows  were  to  be  burned  over 
regularly  each  autumn  the  short-winged  form  would  within  half  a 
century  become  nearly  or  quite  eliminated,  though  the  total  amount  of 

Insect  Life,  Vol,  VII.  pp.  420-422, 1895. 


HIBERNATION. 


15 


injury  to  farm  crops  might  be  thereby  increased  instead  of  diminished. 
It  seems  to  me  that  the  wings  of  the  chinch  bug  were  in  early  days  in 
the  Mississippi  Valley  kept  up  to  a  high  standard  of  development  by 
the  necessity  of  escape  from  prairie  fires  and  not  by  the  presence  of 
Sporotrichium  glob  id  iter  um,  as  suggested  by  Professor  Sajo  in  his 
paper,  a  translation  of  which  is  included  herein  under  the  heading. 
"Habits  of  the  European  species,  Blissus  dorice  Ferr." 

As  mentioned  further  on,  the  advance  of  civilization  having  revolu- 
tionized the  face  of  the  country,  with  this  change  there  has  come  a 
corresponding  one  in  the  hibernating  habits  of  the  chinch  bug,  which 
must  now  seek  shelter  in  the  limited  patches  of  timber  that  are  left  in 
the  sections  that  were  once  entirely  wooded  and  in  the  matted  grass 
along  fences  and  roadsides,  but  especially  among  the  fallen  leaves  and 
rubbish  that  usually  accumulate  along  Osage  orange  hedges.  Brush 
piles,  old  haycocks,  strawstacks,  and,  in  Ohio  at  any  rate,  shocks  of 
corn  fodder  left  standing  in  the  fields  through  the  winter,  all  harbor 
chinch  bugs  during  the  hibernating  season. 

The  fact  of  the  insect  hibernating  in  matted  blue  grass  along  road- 
sides and  fences  has  been  called  in  question  by  Professor  Forbes  and 
by  Mr.  Marlatt,  the  former  in  his  first  report  as  State  entomologist  of 
Illinois  (p.  37)  and  the  latter  in  Insect  Life  (Vol.  VII,  p.  232),  but  not- 
withstanding this,  in  some  parts  of  Ohio,  in  Indiana  and  Illinois,  they 
do  hibernate  in  just  such  places  and  can  be  found  there,  especially 
during  the  winter  and  early  spring  following  a  season  of  abundance, 
but  the  investigator  must  know  how  to  search  for  them.  I  have  found 
them  late  in  the  fall  collected  under  rails,  half  buried  in  soil  and  dead 
grass,  and  in  northern  Illinois  while  searching  for  other  insects  in 
early  spring  I  was  sure  to  find  them  in  varying  numbers  with  small 
Carabida*,  Staphylinida-,  and  other  early-appearing  insects,  on  the 
under  side  of  boards  laid  down  in  grassy  places,  though  no  amount  of 
searching  the  grass  itself  would  have  revealed  their  presence. 

In  the  timothy  meadows  of  northeastern  Ohio  the  percentage  of  long- 
winged  individuals  is  always  much  greater  in  fall  than  in  June,  show- 
ing that  some,  at  least,  hibernate  there  and  migrate  to  the  cultivated 
fields  in  spring.  In  Kansas,  where  Mr.  Marlatt  made  his  observations, 
there  was  still  too  much  prairie,  and  the  species  was  doubtless  still 
adhering  to  its  ancient  habits  of  hibernation.  In  southern  Ohio  I 
have  found  tbem  attacking  the  wheat  in  May,  in  small  isolated  spots 
over  the  fields,  while  there  was  nothing  in  the  least  to  imply  an  inva- 
sion from  outside,  but  the  wheat  had  been  sown  in  the  fall  among  corn, 
and  later  the  corn  stalks  cut  off  and  shocked,  remaining  in  this  condi- 
tion until  the  following  spring.  This  occurred  so  frequently  that  there 
seemed  no  room  to  doubt  that  the  attacks  had  been  caused  by  adults 
wintering  over  in  the  corn  fodder,  and  that  these  left  their  winter 
quarters  in  spring  to  feed  and  breed  on  the  grain  growing  nearest  at 
hand. 


16 


THE  CHINCH  BUG. 


Prof.  Herbert  Osborn,*  in  giving  a  summary  of  his  observations  on 
the  chinch  bug  in  Iowa  in  1894,  states  that  "In  a  great  majority  of 
cases,  90  per  cent  or  more,  the  infested  fields  were  directly  adjacent  to 
hedges  or  thickets  or  belts  of  timber,  and  in  75  per  cent  Osage  orange 
hedges  were  the  most  available  shelter.  In  about  13  per  cent  of  the 
cases  the  evidence  showed  hibernation  in  grass  and  weeds,  and  in  some 
of  these  cases  there  could  scarcely  be  a  doubt  that  the  hibernating  bugs 
were  protected  by  a  heavy  growth  of  grass  or  weeds  and  that  they 
moved  from  these  directly  into  the  adjacent  grain  fields."  Prof.  Law- 
rence Bruner  had  previously  called  attention  to  the  fact  that  the 
chinch  bug  hibernated  in  great  numbers  about  Osage  orange  hedges  in 
Nebraska.  Dr.  Lugger,  in  Minnesota,  gives  the  following  as  offering 
shelter  to  the  bugs  during  winter:  "Rubbish  of  all  kinds,  but  chiefly 
that  of  hedges,  wind-breaks,  and  along  the  edges  of  woods,  as  well  as 
corn  fodder,  logs,  and  even  loose  bark  and  stones.17 

Just  why  an  insect  that  is  apparently  so  unaffected  by  cold,  even 
under  the  most  adverse  circumstances,  should  seek  shelter  at  all  from 
the  elements  is  somewhat  of  a  problem.  While  drenching  rains  are 
beyond  all  possible  doubt  fatal  to  the  newly  hatched  young,  the  adult 
bugs  seem  to  be  almost  proof  against  either  wet  or  cold  weather.  It  is 
doubtless  true  that  very  many  individuals  die  in  their  winter  quarters, 
and  in  fact  I  have  found  these  dead  in  considerable  numbers  in  some 
instances  during  early  spring,  but  it  seems  at  least  doubtful  if  either 
cold  or  wet  would  entirely  account  for  this  fatality.  I  can  but  feel 
that,  somewhere  and  at  some  period  in  the  past,  this  hibernation  has 
been  more  for  protection  from  natural  enemies  than  against  the  ele- 
ments, though  of  course  there  might  have  been  other  reasons  not  dis- 
cernible under  its  changed  environment.  The  pupa  hides  away  to  molt, 
though  it  does  not  appear  that  this  course  is  followed  in  the  earlier 
stages,  and  the  reasons  for  this  are  not  at  all  clear.  That  the  adult  is 
able  to  withstand  combined  cold  and  wet  weather  is  amply  proved  by 
the  observations  of  several  people.  Dr.  Hy.  Shimer,  in  Illinois,  found 
that  those  which  were  in  corn  husks  filled  with  ice,  even  inclosing  the 
chinch  bugs  themselves  in  the  crystallized  element,  when  they  were 
thawed  out  were  able  to  run  about,  apparently  unaffected  by  a  tem- 
perature that  had  varied  from  15°  to  20°  below  zero  Fah.  It  seemed  that 
when  exposed  to  the  sweeping  prairie  winds  at  that  temperature,  with 
no  protecting  cover,  they  perished.  A  Mr.  G.  A.  Waters,  in  the  Farm- 
ers' Review  for  October  19, 1887,  relates  that  a  bunch  of  fodder  having 
fallen  into  a  ditch,  washed  out  near  a  corn  shock  by  heavy  rains,  became 
overflowed  with  water  that  stood  over  the  fodder  long  enough  for  a 
sheet  of  ice  to  form  over  it.  When  the  water  had  subsided  the  corn 
was  husked  and  a  number  of  chinch  bugs  were  found  among  the  ears, 
where  they  had  been  immersed  for  a  week  or  more;  yet  on  being 
exposed  to  the  warm  sun  they  began  to  crawl  about  in  a  lively  manner. 


*  Chinch  Bug  Observations  in  Iowa  in  1894,  Insect  Life,  Vol.  VII,  pp.  230-231. 


SPRING,  SUMMER,  AND  AUTUMN  MIGRATIONS. 


17 


Some  very  similar  instances  of  the  tenacity  of  life  among  chinch  bugs 
have  been  related  to  me  by  farmers  in  Ohio,  so  that  I  have  no  reason 
for  doubting  these  statements.  It  is  more  than  likely  that  the  insect 
seeks  to  protect  itself  from  its  enemies  during  a  period  when  it  will  be 
helpless,  and  also  from  sudden  and  radical  changes  in  temperature. 

SPRING,  SUMMER,  AND  AUTUMN  MIGRATIONS. 

If  there  is  an  ample  supply  of  proper  food  close  at  hand  the  chinch 
bug  simply  crawls  from  its  hibernating  place,  but  if  it  is  in  the  timo- 
thy meadows  of  northeastern  Ohio  it  does  nothing  but  continue  its 
ravages  where  it  left  off  the  autumn  before,  except  a  portion  of  the 
long- winged  form,  which  very  evidently  fly  to  the  wheat  and  corn  fields. 
In  wheat  fields,  unless  the  migration  has  been  from  an  adjoining  field, 
in  which  case  the  attack  is  made  along  the  edge  nearest  thereto,  the 
females  do  not  seem  to  entirely  forsake  their  gregarious  habits,  as 
they  do  not  scatter  out  evenly  over  the  entire  field,  but  appear  to 
locate  in  colonies,  and  when  the  young  hatch  and  begin  to  attack  the 
growing  grain  their  presence  is  first  disclosed  by  small  whitening 
patches,  which  increase  in  dimensions  as  the  young  become  older  and 
more  numerous.  In  low-lying  fields  these  whitening  patches  more 
commonly  appear  on  the  back  furrows  or  on  any  slight  elevations  that 
occur  in  the  field.  But  on  higher  and  level  ground  the  whitening  areas 
are  observed  scattered  over  the  entire  field,  and  constantly  widening 
until  the  whole  field  appears  to  ripen  prematurely  and  crinkle  down. 
When  the  migration  is  accomplished  by  crawling,  the  females  seem  to 
spread  only  enough  to  afford  food  for  the  young  until  the  latter  are 
able  to  make  their  own  way  from  place  to  place.  The  young  remain 
clustered  on  the  plant  about  which  they  were  hatched  until  this  has 
been  drained  of  sap,  when  they  make  their  way,  almost  in  a  body,  to  a 
second  plant,  and  in  this  way  an  attack  will  be  pushed  forward  day 
after  day. 

In  the  spring  the  chinch  bug  probably  lingers  about  its  winter  quar- 
ters until  a  favorable  day  occurs  during  which  to  migrate.  Transfer  a 
typical  Indian  summer  day  to  early  May,  and  perhaps  raise  the  tem- 
perature a  few  degrees,  and  you  have  a  day  during  which  chinch  bugs 
may  be  seen  on  the  wing,  crawling  along  on  fences,  or  at  rest  on  the 
tops  of  fence  posts  as  if  taking  observations,  and  in  reality,  as  I  have 
come  to  believe,  to  catch  the  scent  of  wheat  or  corn  fields.  It  is  on 
just  such  a  day  as  this  that  Aphodius  served  will  be  observed  posted  in 
precisely  the  same  way,  opening  and  closing  the  leaves  of  its  antenna?, 
evidently  to  catch  the  scent  of  the  fresh  droppings  of  animals.  The 
same  movements  characterize  Aphodius  inquinatus  duriug  the  Indian 
summer  days  of  autumn.  I  have  also  observed  the  plum  curculio,  Cono- 
trachelus  nenuphar,  acting  in  precisely  the  same  way  in  late  autumn. 

While  discussing  the  subject  of  chinch-bug  migrations,  it  maybe  best 
to  state  here  that  there  is  a  second  flight  of  chinch  bugs  in  summer 
5968— No.  15  2 


18 


THE  CHINCH  BUG. 


after  the  majority  have  become  fully  developed,  and  not  as  they  reach 
the  adult  stage,  as  Professor  Sajo  has  found  to  be  the  case  with  the 
European  species,  Blissus  doriw.  A  migration  by  flight  takes  place  in 
the  fall,  usually,  I  believe,  during  the  period  of  Indian  summer.  The 
magnitude  of  such  migrations  depends  in  the  spring  on  the  number  of 
individuals  that  have  been  in  hibernation  and  in  the  summer  and  fall 
entirely  on  the  abundance  of  the  species  during  the  current  year.  If 
there  has  been  no  great  abundance  during  the  spring  the  summer 
Might  will  not  be  likely  to  attract  attention.  During  the  invasion  of 
1896  in  Ohio  an  individual  alighted  on  my  hand  while  I  was  riding  on 
a  street  car  in  the  heart  of  the  city  of  Columbus.  A  heavy  storm  of 
rain  has  much  influence  in  scattering  the  bugs  in  midsummer,  and  just 
preceding  a  heavy  rain  I  have  noted  the  fully  developed  adults  very 
abundant  ou  Indian  corn  plants,  while  immediately  after  the  storm 
there  would  be  very  few  to  be  found.  As  these  storms  were  not  always 
accompanied  by  high  winds,  I  am  led  to  believe  that  it  is  the  rainfall 
that  scatters  the  insects. 

In  timothy  meadows  where  the  original  attack  has  begun  along  one 
side  and  gradually  extended  inward,  the  line  of  separation  between 
the  entirely  dead  grass  and  the  uninjured  is  frequently  not  over  a  yard 
in  width,  and  within  this  narrow,  irregular  strip  we  may  have  the  dead 
and  brown,  the  yellowing  indicating  more  or  less  serious  injury  and 
the  perfectly  healthy  green  of  unattacked  plants.  This  many-colored 
border  may  change  but  little  in  the  space  of  a  week  or  ten  days,  except 
to  advance  very  materially,  leaving  the  grass  completely  dead  or  dried 
up,  while  the  clover  plants  were  uninjured.  This  indicates  that  the 
females,  after  leaving  their  places  of  hibernation,  do  not  spread  out 
over  any  large  area,  but  to  a  certain  degree  maintain  their  gregarious 
habits.  I  can  but  believe  that  these  habits  have  been  shaped  by  some 
past  environment  in  which  the  species  has  been  placed  for  a  long  period 
of  time,  as,  for  illustration,  the  inhabiting  of  bunches  or  tufts  of  grass 
more  or  less  isolated  from  each  other. 

To  what  extent  pairing  takes  place  in  these  places  of  hibernation 
before  the  insects  make  their  way  to  the  cultivated  crops  is  a  matter 
of  considerable  uncertainty.  From  my  own  observations  I  am  not 
inclined  to  believe  that  more  than  a  very  insiguiflcant  minority  follow 
this  course. 

OVIPOSITION. 

According  to  most  writers  the  eggs  are  deposited  either  about  or 
below  the  surface  of  the  ground,  among  the  roots  of  the  grass  or  grain. 
It  is  more  than  likely  that  this  varies  with  the  conditions,  as  the  eggs 
are  not  infrequently  found  above  ground  about  the  bases  of  the  plants, 
and  even  upon  the  leaves,  though  I  have  never  found  them  there, 
but  have  often  found  them  under  the  sheath  of  grasses.  It  would 
seem,  then,  that  the  eggs  require  a  cool,  damp,  but  not  a  wet  locality. 


DESCRIPTION  OF  DIFFERENT  STAGES  OF  DEVELOPMENT.  19 


EGG  PKRIOD  AND  NUMBER  OF  EGGS  DEPOSITED  BY  EACH  FEMALE. 

Dr.  Shinier  states  that  each  female  deposits  500  eggs,  scattering 
them  over  a  period  of  from  ten  days  to  three  weeks,  and  as  the  adult 
develops  iii  fifty-seven  to  sixty  days  after  the  eggs  are  deposited,  or 
about  forty-two  days  after  hatchiug.  it  will  be  seen  that  some  of  the 
earliest  hatched  young  are  well  aloug  toward  full  development  by  the 
time  the  last  eggs  are  being  deposited.  According  to  Dr.  Eiley 
the  eggs  hatch,  on  the  average,  in  two  weeks. 

In  a  series  of  breeding- cage  experiments  Prof.  W.  G.  Johnson  found 
that  each  female  deposited  from  98  to  237  eggs,  the  egg  period  lasting 
from  eighteen  to  twenty-one  days,  the  period  of  ovipositiou  covering 
from  thirty-eight  to  forty-two  days.  Forbes  also  records  in  his  Fifth 
Eeport  (p.  44)  experiments  showing  that  the  period  of  incubation  may 
extend  from  twelve  to  twenty-two  days.  (See  Forbes's  19th  Eeport, 
pp.  177-183.)  It  must  be  remembered,  however,  that  Professor  John- 
son had  but  six  females  employed  in  his  experiments  and  that  these 
were  necessarily  under  an  artificial  environment. 

DESCRIPTIONS  OF  THE  DIFFERENT  STAGES  OF  DEVELOPMENT. 

The  following  descriptions  of  the  egg  and  various  stages  of  the 
young  bugs  are  taken  from  Riley's  Seventh  Missouri  Eeport,  while  that 

of  the  adult  is  from  the  origi- 
nal by  Thomas  Say,  as  pub- 
lished in  his  American  En- 
tomology (Vol.  I,  p.  329, 
LeConte.  Ed.). 

The  egg. — Average  length,  0.03 
inch,  elongate-oval,  the  diameter 
scarcely  one-fifth  the  length.  The 
top  squarely  docked  and  sur- 
rounded with  four  small,  rounded 
tubercles  near  the  center.  Color 
when  newly  laid,  pale  and  whitish 
and  translucent,  acquiring  with 
age  an  amber  color,  and  tiually 
showing  the  red  parts  of  the  em- 
bryo, and  especially  the  eyes 
toward  the  tubernaded  end.  The  size  increases  somewhat  after  deposition,  and  will 
sometimes  reach  near  0.04  inch  in  length.    (Fig.  2,  a,  b.) 

Larval  stages. — The  newly  hatched  larva  is  pale  yellow,  with  simply  an  orange, 
i  colored)  stain  on  the  middle  of  the  three  larger  abdominal  joints.  The  form  scarcely 
differs  from  that  of  the  mature  bug.  being  but  slightly  more  elongate;  but  the  tarsi 
have  but  two  joints  and  the  head  is  relatively  broader  and  more  rounded,  while  the 
joints  of  the  body  are  snbequal,  the  prothoracic  joint  being  but  slightly  louger  than 
any  of  the  rest.  The  red  color  soon  pervades  the  whole  body,  except  the  first  two 
abdominal  joints,  which  remain  yellowish,  and  the  members,  which  remain  pale. 

After  the  first  molt  the  red  is  quite  bright  vermilion,  contrasting  strongly  with  the 
pal**  band  across  the  middle  of  the  body:  the  prothoracic  joint  is  relatively  longer 
and  the  metathoiacic  relatively  shorter.    The  head  and  prothorax  are  dusky  and 


Fig.  2. — Blissus  Itucopterus:  a.  b,  eggs:  c.  newly  batched 
larva:  d,  its  tarsus :  e.  larva  alter  first  molt ;  /,  same  after 
second  molt:  g.  pupa— the  natural  sizes  indicated  at 
sides;  h,  enlarged  leg  of  perfect  bug:  j,  tarsus  of  same 
still  more  enlarged  ;  i.  proboscis  or  beak,  enlarged  (from 
Riley.. 


20 


THE   CHINCH  BUG. 


coriaceous,  and  two  broad  marks  on  the  mesothorax,  two  smaller  ones  on  the  meta- 
thorax,  two  on  the  fourth  and  fifth  abdominal  sutures,  and  one  at  tip  of  abdomen 
are  generally  visible,  but  sometimes  obsolete  ;  the  third  and  fourth  joints  of  antenna; 
are  dusky,  but  the  legs  still  pale.  After  the  second  molt  the  head  and  thorax  are 
quite  dusky  and  the  abdomen  duller  red,  but  the  pale  transverse  band  is  still  distinct; 
the  wing  pads  become  apparent,  the  members  are  more  dusky,  there  is  a  dark-red 

shade  on  the  fourth  and  lifth  abdominal  joints,  and 
ventrally  a  distinct  circular  dusky  spot,  covering  the 
last  three  joints.    (Fig.  2,  c,  df  e,f.) 

The  pupa. — In  the  pupa  the  coriaceous  parts  are 
brown-black ;  the  wing-pads  extend  almost  across  the 
two  pale  abdominal  joints,  which  are  now  more  dingy, 
while  the  general  color  of  the  abdomen  is  dingy  gray; 
the  body  above  is  slightly  pubescent,  the  members  are 
colored  as  in  the  mature  bug,  the  three-jointed  tarsus 
is  foreshadowed,  aud  the  dark,  horny  spots  at  tip 
of  abdomen,  both  above  and  below,  are  larger. 
(Fig.  2,  g.) 

The  adult. — Blackish,  hemelytra  white,  with  a  black 
spot. 

Inhabits  Virginia. 

Fig.  3.— Blisms  leucopterus:  Body  long,  blackish,  with  numerous  hairs.  Antenna* , 
adult  of  long-winged  form—  rather  short  hairs ;  second  joint  yellowish,  longer  than 
much  enlarged  ^original).  the  third ;  ultimate  joint  rather  longer  than  the  second, 

thickest;  thorax  tinged  with  cinereous  before,  with 
the  basal  edge  piceous;  hemelytra  white,  with  a  blackish  oval  spot  on  the  lateral 
middle:  rostrum  and  feet  honey  yellow;  thighs  a  little  dilated. 
Length  less  than  three-twentieths  of  an  inch. 
Took  a  single  specimen  on  the  eastern  shore  of  Virginia. 

The  whiteness  of  the  hemelytra  in  which  is  a  blackish  spot  strongly  contrasted 
distinguishes  this  species  readily. 


Fig.  4. — Blissus  leucopterus :  adults  of  short-winged  form — much  enlarged  (original). 

To  the  foregoing  description  of  the  adult  Dr.  Asa  Fitch,  in  his 
second  report  on  the  Insects  of  Xew  York,  adds  brief  descriptions  of 
nine  varieties,  all,  with  but  one  exception,  being  based  upon  slight 
variations  in  color,  some,  perhaps,  being  due  to  immaturity,  the  single 
exception  being  the  short-winged  inlaud  form,  of  which  variations  from 
the  nearly  wingless  to  fully  winged  are  shown  in  tigs.  3  aud  4. 


DEVELOPMENT  AND  HABITS  OF  THE  YOUNG. 


21 


Leaving,  then,  out  of  consideration  the  color  varieties  as  arranged 
by  Dr.  Fitch,  we  have  a  long-winged  form,  in  which  individuals  from 
the  eastern  portion  of  the  country  differ  from  those  found  in  the  West 
by  being  more  hairy  and  robust,  as  pointed  out  by  Mr.  Van  Duzee;  a 
short-winged  form,  found  along  the  seacoast,  and  a  similar  inland  form 
differing  from  this  last  chiefly  in  its  more  robust  body,  broader  and 
usually  much  more  abbreviated  wings. 

DEVELOPMENT  AND  HABITS  OF  THE  YOUNG. 

The  newly  hatched  young  are  very  active,  and  the  first  to  appear 
may  be  observed  with  their  progenitors  about  the  bases  of  wheat,  corn, 
or  grass  plants,  and  later  all  stages  are  seen  mingling  together,  having 
little  appearance  of  belonging  to  the  same  species,  so  greatly  do  they 
vary  in  size  and  color  in  their  several  stages  of  development. 

As  a  rule  the  bugs  confine  themselves  to  the  lower  portion  of  the 
plants  attacked,  but  may  later  push  their  way  upward,  especially  if 
the  lower  portion  becomes  tough  and  woody,  finally  covering  it  in 
patches,  as  seen  in  fig.  5,  where  they  are  shown  on  a  stalk  of  young 
corn.  Mr.  E.  A.  Schwarz  relates  a  curious  exception  to  this  habit  in 
Florida  upon  sand  oats,  UnivJa  paniculata,  where  the  entire  develop- 
ment of  the  insect  is  undergone  upon  the  highest  part  of  this  tall 
plant  and  not  close  to  the  bottom.  Mr.  Schwarz  has  given  as  a  proba- 
ble reason  for  this  the  fact  that  strong  winds  are  continually  blowing 
the  fine,  sharp  sand  through  among  the  lower  parts  of  the  plants, 
rendering  it  nearly  or  quite  impossible  for  the  bugs  to  remain  in  that 
situation,  thus  forcing  them  to  seek  their  sustenance  farther  up  the 
plants.  While  the  figure  just  referred  to  gives  a  good  representation 
of  the  appearance  of  a  corn  plant  when  the  chinch  bugs  are  present  in 
excessive  numbers,  yet  the  writer  has  invariably  found  that  they  much 
prefer  a  stalk  that  has  been  blown  down  by  the  wind  or  partly  broken 
off  by  the  plow  and  left  lying  nearly  flat  upon  the  ground. 

In  timothy  meadows  the  very  young  are  to  be  found  only  by  pulling 
away  the  soil  from  about  the  bulbous  roots  and  drawing  down  the  dead 
sheaths  that  usually  envelop  them.  An  observer  may  even  pull  up  a 
tuft  of  grass  entire,  and  yet,  unless  he  examines  in  this  way  closely, 
may  overlook  them,  so  snugly  are  they  thus  ensconced  among  the  roots. 
If  driven  to  forsake  a  tuft  of  grass  the  young  bugs  move  to  another 
and  crawl  downward,  and  are  soon  to  be  found  as  snugly  settled  as 
before.  It  is  only  when  they  are  older  and  well  advanced  toward 
maturity  that  they  work  to  any  extent  above  ground,  and  even  then 
only  in  cases  where  they  are  present  in  great  numbers.  Singularly 
enough,  where  infested  meadows  are  plowed  up  and  planted  with  corn 
the  females  seem  to  forsake  the  young  corn  plants  and  select  the  occa- 
sional stray  clumps  of  timothy  that  cultivation  has  failed  to  destroy 
and  deposit  their  eggs  about  these,  so  that  later  the  young  may  be 
swarming  about  these  last,  while  hardly  one  is  to  be  found  about  the 


22 


THE  CHINCH  BUG. 


young  corn.  This  is  precisely  the  opposite  of  what  is  observed  farther 
west. 

Although  living  externally  on  their  food  plants,  and  not  withstanding 
the  young  may  attack  the  bases  or  even  the  roots  of  some  of  these, 
yet  the  species  is  essentially  an  external  feeder,  and  appears  while  thus 
engaged  almost  totally  indifferent  to  possible  attacks  of  natural  ene- 
mies. When  not  feeding,  however,  there  is  at  times  a  tendency  to 
hide  awa}-  under  the  sheaths  of  young  corn  or  beneath  clods  of  earth 
or  bunches  of  coarse  stable  manure,  where  this  has  been  recently 
applied  and  left  more  or  less  exposed  on  the  surface  of  the  ground.  I 
have  noted  this  in  cases  where  neither  an  uncomfortable  temperature 
nor  wet  weather  necessitated  protection. 

As  has  been  shown  in  the  description  of  the  larval  stages,  there  are 
four  molts  between  the  egg  and  the  adult  state.  Just  how  the  molting 
larvae  act  I  have  never  been  able  to  determine ;  neither  have  I  wit- 
nessed pupation,  but  a  fully  developed  pupa  that  is  ready  to  molt  is 
easily  distinguished  by  its  larger  size  and  more  tightly  fitting  skin,  which 
is  almost  shining  white  on  the  median  ventral  surface  of  the  abdomen. 
It  now  hides  itself  away,  seemingly  preferring  to  get  under  the  sheaths 
of  grasses  or  grains;  but  if  these  are  not  convenient  it  will  crawl  under 
loose  clods,  or  even  into  crevices  in  the  ground.  While  thus  hidden 
away  the  pupa  skin  splits  along  the  back  and  the  fully  developed  adult 
makes  its  way  out,  leaving  the  empty  skins  behind,  which  last  are  very 
frequently  mistaken  for  dead  chinch  bugs,  and,  when  mold}7,  the 
farmer  is  very  likely  to  suppose  that  they  are  bugs  which  have  been 
killed  by  the  fungus  Sporotrichum  globuliferum,  if  this  has  been 
applied  in  the  fields. 

On  first  emerging  from  the  pupa  the  adult  is  generally  of  a  dull  pink 
color,  except  the  wings,  which  are  white,  exclusive  of  the  veins,  these 
being  of  the  same  pinkish  hue  as  the  body.  In  a  short  time  these  col- 
ors change  to  the  normal  ones  of  the  species,  but  during  the  breeding 
season  these  newly  developed  adults  may  be  observed  crawling  about 
with  the  young  of  all  stages  as  well  as  the  maturely  colored  adults. 

If  this  development  has  been  taking  place  in  a  wheat  field  and  the 
grain  is  harvested  at  this  time,  or  if  from  any  other  cause  the  food  sup- 
ply becomes  suddenly  exhausted,  all  sizes  of  larvae  with  pupae  and 
adults  will  start  oft*  on  foot  to  hunt  for  a  fresh  supply.  Though  many 
individuals  may  now  have  become  fully  developed,  and,  so  far  as  can  be 
determined,  possess  wings  entirely  fitted  for  active  service,  neverthe- 
less they  will  crawl  along  a  dusty  road  or  across  freshly  plowed  fields 
in  company  with  their  less  fortunate  fellows,  seemingly  never  for  a 
moment  supposing  that  they  can  span  the  intervening  space  by  flight. 
The  writer  is  totally  unable  to  account  for  this  phenomenon  in  the 
species  at  this  time,  the  disinclination  to  use  the  wings  being  so  wholly 
unlike  the  habits  of  />.  dories,  as  shown  by  the  careful  and  painstaking 
observations  of  Professor  Sajo  in  Hungary.   Again,  the  seeming  desire 


NUMBER  OF  ANNUAL  GENERATIONS. 


23 


on  the  part  of  the  pupae  to  secrete  themselves  while  transforming  to 
adults  does  not  at  all  coincide  with  the  idea  of  a  supposed  immunity 
from  attacks  of  natural  enemies.  Surely  our  species  of  Blissus  has  not 
always  lived  where  natural  enemies  were  as  few  as  they  are  with  us  at 
the  present  time.  Even  where  we  have  both  the  long-winged  and 
short- winged  forms  occurring  together  in  timothy  meadows,  there  is 
no  such  haste  exhibited  on  the  part  of  the  former  to  escape  from  the 
companionship  of  the  latter,  as  observed  by  Professor  Sajo.  We  know, 
however,  that  our  species  certainly  does  enjoy  a  considerable  immunity 
from  natural  enemies,  though  its  conspicuous  colors  in  both  the  larval  and 
adult  stages  contrast  very  strongly  with  those  of  its  usual  food  plants 
and  its  presence  is  still  further  advertised  by  its  strangely  persistent 
gregarious  habits.  We  have  come  to  suppose  the  species  to  be,  in  part 
at  least,  protected  from  attack  by  its  vile  odor,  and  so,  indeed,  it  may 
be  in  the  United  States,  but  I  fully  believe  that  somewhere  in  its  south- 
ern habitat  it  will  be  found  to  have  one  or  more  enemies,  like  the  ant, 
Eciton  hamata,  of  Central  America,  for  illustration.  Our  native  ants, 
however,  will  seldom  attack  even  the  young. 

NUMBER  OF  ANNUAL  GENERATIONS. 

Over  the  most  of  its  area  of  habitation  in  North  America,  at  least,  the 
chinch  bug  is  two  brooded,  though  in  northeastern  Ohio  I  have  totally 
failed  to  detect  the  second  brood,  or,  in  fact,  to  perceive  any  indica- 
tions that  a  second  brood  occurs ;  but  to  this  I  shall  refer  later.  As 
previously  shown,  there  is  not  sufficient  proof  at  hand  to  warrant  the 
statement  that  there  is  even  in  the  far  South  a  partial  third  brood. 
I  believe  that  the  number  of  annual  broods  of  this  species  has  been 
primarily  decided  in  its  home  in  the  tropical  regions  by  the  wet  and 
dry  seasons  occurring  there,  and  that  we  have  in  the  North  these  same 
broods  occurring  at  slightly  different  periods  under  the  influence  of  a 
change  from  wet  and  dry  to  hot  and  cold  seasons. 

Belt,  in  his  Naturalist  in  Nicaragua,  has  the  following  to  say  with 
regard  to  the  seasons  on  the  northeastern  side  of  that  country:  "The 
rains  set  in  in  May  and  continue  with  occasional  intermissions  until 
the  following  January,  when  the  dry  season  of  a  little  more  than  three 
months  begins  "  (p.  103).  "  The  heaviest  rains  fall  in  July  and  August, 
and  at  those  times  the  brooks  are  greatly  swollen. n  "  In  September, 
October,  and  November  there  are  breaks  of  fine  weather,  sometimes 
lasting  for  a  fortnight,  but  December  is  generally  a  very  wet  month, 
the  rains  extending  far  into  January,  so  that  it  is  not  until  February 
that  the  roads  begin  to  dry  up"  (p.  104).  It  seems  that  we  here  have 
the  possible  key  to  the  secret  of  the  number  of  annual  broods  of  the 
chinch  bug.  That  it  may  be  able  to  adapt  itself  still  further  to  changed 
latitude  and  environments  and  become  single  brooded  is  not  at  all 
impossible.  As  illustrating  the  ease  with  which  insects,  at  least  some 
of  them,  can  change  their  habits  to  correspond  with  their  environment, 


24 


THE  CHINCH  BUG. 


we  have  in  South  Australia  the  following  facts  regarding  the  codling 
moth,  Carpoca/psa  pomonella,  of  which,  though  being  still  double  brooded, 
"  the  winter  caterpillars  hatch  into  moths  irregularly  from  the  begin- 
ning of  October  until  the  middle  of  November  and  deposit  their  eggs 
accordingly,  giving  rise  to  a  succession  of  young  caterpillars  until  the 
beginning  of  December.  About  the  third  week  in  December  the  first 
moths  of  the  second  brood  begin  to  appear  and  deposit  eggs,  and  mem- 
bers of  this  second  generation  of  moths  continue  hatching  and  egg  lay- 
ing until  the  end  of  February."  * 

My  notes  on  the  chinch  bug  in  northeastern  Ohio  are  as  follows: 
Very  young  larvae,  with  what  appeared  to  be  their  progenitors,  were 
observed  at  Jefferson,  Ashtabula  County,  within  11  miles  of  the  shores 
of  Lake  Erie,  on  June  16,  1893,  no  advanced  larva?  being  observed 
among  them.  On  August  27, 1896,  a  few  miles  south,  at  West  Andover, 
in  the  same  county,  I  could  find  only  adults  in  two  days'  search,  though 
some  of  these  showed  by  their  color  that  they  had  but  recently  passed 
the  pupal  stage.  In  this  latter  locality,  on  May  7, 1897,  the  sexes  were 
pairing,  but  no  young  were  present,  so  far  as  could  be  observed,  while 
to  the  south  and  west  of  this  locality,  on  June  8  and  9,  precisely  the 
same  conditions  obtained  as  to  the  bugs,  no  young  appearing  at  this 
time.  Quite  copious  rains  might  have  destroyed  the  young,  but  within 
15  miles  of  these  localities,  on  July  14  of  this  year  also,  I  found  larvae 
after  first  molt  and  stages  intervening  between  these  and  the  adults. 
Near  Youngstown,  on  October  3,  1897, 1  could  find  only  adults  and  pair- 
ing was  not  in  progress,  and  the  insect  was  not  pairing  in  Ashtabula 
County  on  August  27,  1896.  June  9,  1898,  only  two  very  young  larvae 
could  be  found  at  Salem,  about  15  miles  southwest  of  Youngstown.  In 
the  light  of  the  information  that  has  been  gained  by  these  observations 
I  am  led  to  doubt  the  occurrence  of  a  second  brood  of  young  in  north- 
eastern Ohio.  Hatching  is  not  fully  in  progress  here  before  the  25th 
of  June,  only  an  occasional  individual  having  passed  the  first  molt 
before  the  10th  of  July,  t 

The  late  Dr.  J.  A.  Lintner,  in  his  studies  of  the  outbreak  of  this 
insect  in  New  York  State  in  1882  and  1883,  seems  to  have  relied  much 
on  the  published  habits  of  the  species  farther  west  (as  indeed  I  have 
until  receutly  done  myself),  and  made  no  exact  studies  of  the  species  at 
that  time;  and  iu  his  annual  report,  where  the  outbreak  is  discussed,  I 

*  George  Quinu,  iu  Journal  of  Agriculture  and  Industry,  S.  A.,  Vol.  I,  p.  112. 

tUp  to  date  of  revision  of  proof  sheets  of  this  bulletin,  October  17,  1898,  no 
young  of  a  second  brood  have  been  observed  though  careful  search  has  been  made 
from  time  to  time  in  the  fields  and  meadows  of  northeastern  Ohio,  and  a  large 
number  of  adults  which  developed  in  July  and  August,  and  since  kept  in  confine- 
ment, have  not  only  not  reproduced  but  have  shown  no  disposition  whatever  to 
pair.  On  the  other  hand,  in  southwestern  Ohio,  in  the  vicinity  of  Cincinnati,  on 
September  24,  where  the  species  occurred  in  abundance,  fully  seventy-five  per  cent 
were  pupa?,  the  remainder  being  made  up  of  larvaB,  some  of  them  quite  young,  and 
adults  in  about  equal  proportions,  some  of  the  latter  showing  by  their  immature 
colors  that  they  had  but  just  passed  the  pupal  stage. 


NUMBER  OF  ANNUAL  GENERATIONS. 


25 


can  find  no  absolute  proof  of  the  existence  of  a  second  brood  in  ^ew 
York."'  The  occurrence  of  a  second  brood  of  young  in  northern  Illinois, 
as  indicated  by  Dr.  Fitch,  has  always  been  considered  as  settled,  and 
in  a  more  northern  latitude  than  northeastern  Ohio,  so  that  there  must 
be  some  other  influences  besides  latitude  to  account  for  the  phenomenon. 
That  the  species  has  occupied  this  territory  for  many  years  is  indicated 
by  the  observations  of  Mr.  E.  P.  Van  Duzee,  of  Buffalo,  X.  Y.,  who 
wrote  me  that  the  insect  was  as  abundant  twenty-three  years  ago  as 
at  the  present  time,  so  that  whatever  effect  on  the  insect  the  recent 
occupation  of  the  country  might  have  had  that  effect  has  passed  away, 
and  a  condition  of  what  we  might  call  equilibrium  now  exists  here. 

On  July  7,  1889,  in  the  extreme  northern  part  of  Indiana,  the  writer 
found  an  abundance  of  young  which  had  not  yet  molted  for  the  first 
time.  Dr.  A.  S.  Packard  records  adults  as  pairing  at  Salem,  Mass., 
June  17,  1871,  as  quoted  by  Dr.  Lintner,  while  the  latter  gentleman 
records  the  young  as  occurring  in  Lawrence  County,  Xew  York,  about 
July  5, 1883.t 

Hardly  has  the  latest  hatched  young  of  the  first  brood  developed  to 
the  adult  before  the  young  of  the  second  brood  begin  to  appear.  In 
southern  Ohio  this  is  about  the  first  week  in  August.  Generally  these 
young  do  little  injury,  because  the  wheat  has  long  since  been  harvested 
and  the  corn  is  usually  too  far  advanced  and  tough  to  offer  a  desirable 
source  of  food  supply,  except  in  cases  where  fields  have  been  planted 
very  late,  and  here  the  writer  has  known  them  to  work  considerable 
injury,  especially  in  seasons  of  severe  drought  that  prevented  the  rapid 
growth  of  the  plants.  Fall  attacks  of  wheat  are  rare,  and  the  injury  is 
never  of  a  serious  nature,  as  it  is  usually  the  case  that  by  the  time  the 
young  wheat  is  large  enough  to  invite  attack  the  chinch  bugs  are 
searching  for  winter  quarters. 

In  the  timothy  meadows  of  northeastern  Ohio,  however,  the  principal 
injury  is  done  during  August  and  September,  and  in  favorable  weather 
on  into  October.  Xow  if  we  allow  sixty  days  for  development  from  the 
egg.  it  would  be  September  before  the  appearance  of  the  adults  of  the 
brood  to  which  these  various  young  belonged.  If  all  eggs  were  depos- 
ited immediately,  it  would  be  November  before  the  adults  of  the  second 
brood  would  begin  to  occur,  a  condition  of  affairs  that  has  never  been 
observed.  As  previously  shown  in  this  bulletin,  the  first  brood  is  fully 
developed  in  northeastern  Ohio  by  the  first  of  September,  but  there 
certainly  is  no  indication  that  a  second  brood  of  young  is  developed 
during  September  and  October.  It  would  seem  then  that  from  eastern 
Ohio  through  New  York,  New  England,  and  probably  to  Nova  Scotia, 
the  adults  from  the  first  brood  of  larvae  winter  over,  and  that  there  is 
here  but  one  annual  brood. 


*  Second  Repon  of  the  State  Entomologist,  pp.  148-164, 1885. 
t  Loc.  cit.,pp.  158, 159,  164. 


26 


THE  CHINCH  BUG. 


GREGARIOUS  HABITS  OF  THE  CHINCH  BIG. 

I  have  previously  called  attention  to  the  gregarious  habits  of  the 
chinch  bug,  and  only  refer  to  the  phenomenon  again  because  it  is  to 
this  that  its  destructiveness  is  largely  due.  It  is  not  because  of  the 
excessive  numbers,  but  the  persistency  with  which  they  will  congregate 
091  masse  on  limited  areas,  that  renders  their  attacks  so  fruitful  of 
injury.  With  an  ample  supply  of  food  the  young  devehyp  and  leisurely 
diffuse  themselves  over  the  adjacent  fields,  and  there  are  neither 
swarming  flights  nor  migrations.  In  1884,  in  northern  Indiana,  a  small 
field  of  wheat  was  severely  attacked  by  chinch  bugs.  At  harvest 
there  was  every  prospect  of  a  migration  from  the  field  of  wheat  to  an 
adjacent  one  of  corn,  and  the  bugs  were  present  in  sufficient  numbers 
to  have  worked  serious  injury  to  the  latter;  but  the  wheat  had  grown 
up  thinly  on  the  ground,  and  there  had  sprung  up  among  the  grain  a 
great  deal  of  meadow  foxtail  grass,  Setaria  glauea  Beauv.,  and  panic 
grass,  Panicum  crus-galli  L..  and  to  these  grasses  the  bugs  transferred 
their  attention,  finishing  their  development  thereon,  and  later,  so  far  as 
I  could  determine,  they  scattered  by  flight  out  over  the  adjacent  fields, 
working  no  further  injury.  Pedestrian  migrations  may  continue  for  a 
fourth  of  a  mile  or  even  more,  but  on  reaching  a  suitable  food  supply 
the  tendency  is  to  congregate  upon  their  food  plants  until  these  are 
literally  covered  with  chinch  bugs,  varying  in  color  from  the  black  and 
white  adults  to  those  of  the  more  advanced  larva?.  (See  Fig.  5).  What- 
ever tendency  there  is  exhibited  toward  a  wider  diffusion  is  confined  to 
the  adults,  the  others  remaining  and  leaving  in  a  body  only  when  the 
plant  on  which  they  have  congregated  has  been  drained  of  its  juices  and 
has  begun  to  wither,  when  they  simply  crawl  to  the  nearest  plants  and 
again  congregate  upon  them  as  before.  In  case  the  migration  has  been 
to  a  field  of  corn,  and  if  this  is  badly  overgrown  with  either  of  the  two 
grasses  previously  named,  the  bugs  will  collect  upon  the  latter,  and 
unless  the  corn  plants  are  very  small  they  will  not  as  a  rule  attack  them 
until  the  grass  has  been  killed.  Some  farmers  have  gone  so  far  as  to 
claim  a  benefit  to  be  derived  from  a  certain  abundance  of  chinch  bugs, 
the  statement  being  made  that  they  will  kill  out  these  grasses  to  an 
extent  that  nothing  else  will.  It  is  clear  that  the  acquisition  of  wings  is 
not  the  signal  for  the  adults  to  abandon  the  companionship  of  the  larvae 
and  pupae,  yet  they  do  gradually  disappear  from  among  them.  It  is 
possible  that  the  disposition  to  pair  does  not  exist  until  the  individual 
has  reached  a  certain  age  beyond  seeming  maturity,  and  that  it  is  not 
until  the  passion  for  mating  has  overcome  their  gregarious  inclination 
that  they  are  disposed  to  migrate.  Or  it  may  be  that  the  phenomenon 
may  be  explained  on  the  supposition  that  when  the  pairing  season 
approaches  the  males  scatter  out  in  order  to  find  females  with  which 
they  are  not  akin,  thus  following  out  natural  selection  and  preventing 
a  continual  interbreeding.    Over  the  northern  United  States,  at  least, 


FOOD  PLANTS. 


•27 


the  injury  in  cultivated  fields  is  done  almost  entirely  by  the  young 
bugs,  but  in  the  timothy  meadows  the  damage  is  due  as  much,  if  not- 
more,  to  the  depredations  of  the  adults. 

FOOD  PLANTS. 

As  to  food  plants  there  can  be  no  doubt  but  that  these  consisted 
originally  of  the  native  grasses.  This  is  amply  proven  by  the  observa- 
tions of  Fitch  and  Le  Baron,  in  Illinois;  Dr.  J.  G.  BTeal,  in  Florida  and 
Oklahoma;  Marl att, in  Kansas;  Schwarz,  in  Florida;  and,  recently,  by 
those  of  Mr.  Henry  G.  Hubbard,  in  the  midst  of  the  Colorado  desert 
in  California.  Regarding  this  last  statement,  Mr.  E.  A.  Schwarz  has 
written  to  me  -as  follows : 

You  may  be  interested  to  learn  that  chinch  bugs  were  collected  this  year  (1897) 
on  March  28  by  Mr.  H.  G.  Hubbard,  at  Salton,  in  the  midst  of  the  Colorado  desert 
of  California.  This  locality  is  considerably  below  the  ocean  level,  and  represents 
an  ancient  extension  of  the  Gulf  of  California.  Even  at  the  present  time  the  Salton 
Basin  is  occasionally  flooded,  the  water  entering  through  Xew  River,  which  runs 
from  the  mouth  of  the  Colorado  River  into  the  Salton  Basin.  The  specimens  were 
taken  on  a  species  of  coarse  grass  which  is  incrusted  with  a  saline  deposit. 

No  wonder  that  the  chinch  bug  is  accused  of  being  a  seashore 
species ! 

Of  cultivated  grasses,  or  such  as  occur  in  cultivated  fields,  probably 
Setaria  glauea  and  Panicum  crus-galli  are  the  favorites,  though  millet 
and  Hungarian  grass  are  apparently  nearly  as  attractive.  As  early  as 
1845,  in  Illinois,  Dr.  William  Le  Baron,  afterwards  State  entomologist, 
gave  the  food  plants  of  the  chinch  bug  as  follows:  *  *  *  »  all  kinds 
of  grain,  corn,  and  herd's-grass  "  (timothy).*  But  to  this  day  in  Illi- 
nois, as  shown  by  the  observations  of  Professor  Forbes  and  myself,  the 
species  will  attack  timothy  only  in  cases  where  it  is  compelled  to  do  so 
by  reason  of  a  lack  of  other  food.  In  addition  to  the  preceding,  Dr.  How- 
ard gives  broom  corn,  sorghum,  chicken  corn,  Bermuda  grass  (Cynodon 
dactylum),  blue  grass  (Poa pratensis),  crab  grass  (Panicum  sanguinaJe), 
and  bottle  grass  (Setaria  viridis),  and  also  states  that  in  the  rice  fields 
near  Savannah,  Ga.,  in  August,  1881,  he  observed  the  winged  adults 
upon  the  heads.  Prof.  H.  A.  Morgan  writes  me  that  in  1897  it  had 
become  a  serious  enemy  to  u Providence"'  rice  in  Louisiana,  where  for 
two  years  it  had  seriously  injured  corn,  and  I  am  otherwise  informed 
that  it  is  proving  injurious  to  corn  again  in  1898.  I  have  often  found 
the  adults  collected  in  the  silk  of  belated  ears  of  corn  in  the  fields  in 
September,  when  all  other  parts  of  the  plant  had  either  become  too  old 
and  tough  to  afford  nourishment  or  else  had  been  killed  by  the  frosts  of 
autumn.  Prof.  Lawrence  Bruner  has  recorded  the  insect  as  feeding 
upon  so-called  wild  buckwheat  (Polygonum  dumetorum  or  P.  con  volvulus),] 
The  writer  has  never  seen  chinch  bugs  attack  blue  grass  (Poa  pratensis), 

*  Prairie  Farmer,  December,  1845. 

t  Report  Commissioner  of  Agriculture,  1887,  pp.  57-58. 


28 


THE  CHINCH  RUG. 


and  has  seldom  witnessed  an  injury  to  oats.  Over  the  western  country 
the  major  portion  of  the  damage  done  is  to  fields  of  wheat,  barley,  rye, 
and  corn,  the  outbreak  generally  originating  in  wheat  or  barley  fields 


Fig.  5.— Corn  plant  two  feet  tall  infested  with  chinch  bugs  (original). 

and  the  bugs  migrating  at  harvest  to  the  cornfields.  (See  fig.  5.) 
In  Ohio  this  has  been  the  case  except  in  the  eastern  part  of  the  State, 
where  the  timothy  meadows  are  the  most  seriously  infested,  and 


LOSSES  CAUSED  BY  CHINCH  BUGS. 


29 


here  the  migrations  are  as  likely  to  be  to  the  timothy  meadows  as  to 
the  fields  of  corn,  where  both  are  equally  within  reach.  Besides, 
everything  indicates  that  a  very  large  proportion  of  the  adults  may 
hibernate  in  these  meadows,  even  making  their  way  thereto  in  the 
autumn. 

LOSSES  CAUSED  BY  CHINCH  BUGS. 

It  would  appear  that  this  pest  first  made  its  presence  known  by  its 
ravages  iu  the  wheat  fields  of  the  North  Carolina  farmers;  for  we  are 
told  that  "  in  1785  the  fields  in  this  State  were  so  overrun  with  them  as 
to  threaten  a  total  destruction  of  the  grain.  And,  at  length  the  crops 
were  so  destroyed  in  some  districts  that  farmers  were  obliged  to  abandon 
the  sowing  of  wheat.  It  was  four  or  five  years  that  they  continued  so 
numerous  at  this  time."* 

In  the  year  1809,  as  stated  by  Mr.  J.  W.  Jefferys,t  the  chinch  bug 
again  became  destructive  in  North  Carolina  to  such  an  extent  that  in 
Orange  County  farmers  were  obliged  to  suspend  the  sowing  of  wheat 
for  two  years.  In  1839}  the  pest  again  became  destructive  in  the 
Caroliuas  and  in  Virginia,  where  the  bugs  migrated  from  the  wheat 
fields  at  harvest  to  the  corn,  and  in  1840  there  was  a  similar  outbreak 
and  both  wheat  and  corn  were  seriously  injured.  In  all  of  these  cases, 
however,  there  is  no  recorded  estimate  of  the  actual  financial  losses 
resulting  from  the  attacks  of  the  chinch  bug.  According  to  Le  Baron, 
during  the  years  from  1845  to  1850  the  insect  ravaged  over  Illinois  and 
portions  of  Indiana  and  Wisconsin,  and  in  1854  and  1855  it  again 
worked  serious  injury  in  northern  Illinois.  The  writer's  earliest  recol- 
lection of  the  chinch  bug  and  its  ravages  in  the  grain  fields  of  the 
settlers  on  the  prairies  dates  from  this  last  outbreak.  Mr.  B.  D.  W  alsh 
estimated  the  loss  to  the  farmers  of  Illinois  in  1850  at  $4,000,000,  or 
$4.70  to  every  man,  woman,  and  child  living  in  the  State.  The  earlier 
outbreaks,  though  the  occasion  of  smaller  money  loss,  were  even  more 
disastrous  ;  for  the  destruction  of  the  grain  crops  in  those  pioneer  days 
not  only  took  away  all  cash  profits,  but  also  deprived  the  early  settlers 
of  their  very  living,  and  in  some  cases  reduced  them  to  starvation. 

In  1863,  1864,  and  1865  the  insect  was  again  destructive  in  Illinois 
and  other  Western  States,  its  ravages  being  especially  severe  in  1864, 
when  we  have  another  attempt  at  computation  of  the  financial  loss. 
Dr.  Henry  Shimer,  of  Mount  Carroll,  111.,  who  had  carefully  studied 
the  chinch  bug,  estimated  that  "three-fourths  of  the  wheat  and  one- 
half  of  the  corn  crop  were  destroyed  by  the  pest  throughout  many 
extensive  districts,  comprising  almost  the  entire  northwest."  In  criti- 
cising the  doctor  regarding  another  point,  Messrs.  Walsh  and  Riley,  in 
The  American  Entomologist  (Vol.  I,  p.  197,  1869),  admit  that  the 

Webster  on  Pestilence,  Vol.  I,  p.  279.    Not  seen.    Quoted  from  Fitch, 
t  Albany  Cultivator,  first  series,  Vol.  VI,  p.  201. 
t  The  Cultivator,  Vol.  VI,  p.  103. 


30 


THE  CHINCH  BUG. 


estimate  was  "a  reasonable  one,1'  and,  taking  it  as  a  basis,  with  the 
actual  cash  price  per  bushel,  computed  the  loss  at  about  30,000,000 
bushels  of  wheat  aud  138,000,000  bushels  of  corn,  with  a  total  value 
of  both  amounting  to  over  $73,000,000.  Of  course  all  computations  of 
this  sort  are  necessarily  only  approximately  correct,  but  there  is  more 
likelihood  of  an  under  than  an  over  estimate  in  this  case. 

There  was  a  serious  outbreak  of  the  chinch  bug  in  the  West  again  in 
the  year  1808,  and  again  in  1871,  but  in  1874  the  ravages  were  both 
widespread  and  enormous.  Dr.  LeBaron  computed  the  loss  in  1871 
in  seven  States,  viz,  Iowa,  Missouri,  Illinois,  Kansas,  Nebraska,  Wis- 
cousiu,  and  Indiana,  at  $30,000,000.*  Dr.  C.  V.  Riley  computed  the 
loss  in  Missouri  alone  in  the  year  1874  at  $19,000,000,  and  added  the 
statement  that  for  the  area  covered  by  Dr.  LeBaron's  estimates  in  1871 
the  loss  in  1874  might  safely  be  put  down  as  double,  or  upward  of 
$60,000,000.  f  Dr.  Cyrus  Thomas,  however,  estimates  the  loss  to  the 
whole  country  for  the  same  year  at  upward  of  $100,000,000.  £ 

The  next  serious  outbreak  of  chinch  bug  of  which  we  have  the 
losses  resulting  therefrom  computed,  occurred  in  1887,  and  covered 
more  or  less  territory  in  the  States  of  Kentucky,  Ohio,  Indiana,  Illinois, 
Wisconsin,  Minnesota,  Iowa,  Missouri,  and  Kansas.  In  this  case  the 
damage  was  estimated  by  the  United  States  statistician,  Mr.  J.  E. 
Dodge,  at  $60,000,000,  the  heaviest  losses  occurring  in  Illinois,  Iowa, 
Missouri,  and  Kansas.  §  This  gives  us  as  the  estimated  loss  in  the 
thirty  eight  years,  1850  to  1887,  both  inclusive,  the  enormous  sum  of 
$267,000,000. 

There  was  a  serious  outbreak  in  Kansas,  Iowa,  Minnesota,  and  Illi- 
nois, having  its  beginning  probably  as  early  as  1892,  but  reaching  its 
maximum  severity,  as  in  Ohio,  in  1896.  The  loss  in  Ohio  during  the 
years  1894,  1895,  1896,  and  1897  could  not  have  fallen  far  short  of 
$2,000,000.  The  farmers  of  this  State  in  many  cases  were  entirely 
unfamiliar  with  the  chinch  bug  and  its  ravages,  and  therefore  were 
unable  to  account  for  the  damage  that  it  worked  in  their  fields  until 
some  time  after.  This  was  especially  true  of  the  timothy  meadows  in 
the  northeastern  part  of  the  State;  so  that  there  were  probably  many 
fields,  both  of  grass  and  of  grain,  that  suffered  seriously,  and,  in  fact, 
in  some  cases  were  ruined  by  the  chinch  bug  without  the  owners  being 
aware  of  the  cause.  For  this  reason,  while  the  computed  loss  appears 
large,  it  seems  to  me  to  be  entirely  reasonable.  Of  the  losses  occasioned 
in  other  States  during  the  years  above  indicated  I  have  no  definite 
computations,  but  they  were  severe,  and  must  have  amounted  to  mil- 
lions of  dollars.  If  we  could  have  careful  estimates  of  the  loss  during 
the  last  seven  years,  it  would  in  all  probability  swell  the  amount  to 

\  *  Second  Report  State  Entomologist  of  Illinois,  p.  144. 

t  Seventh  Report  State  Entomologist  of  Missouri,  pp.  24-25. 
I  Bulletin  No.  5,  U.  S.  Entomological  Commission,  p.  7. 
$  Report  of  U.  S.  Commissioner  of  Agriculture,  1887,  p.  56. 


NATURAL  CHECKS. 


31 


fully  $330,000,000  for  the  period  from  1850  to  1898.  If  the  indirect 
losses  were  to  be  added  the  amount  would  indeed  be  enormous.  Dur- 
ing the  outbreak  in  Ohio  at  least  two  farmers  became  discouraged,  and, 
thinking  that  the  loss  of  their  crops  by  the  attack  of  chinch  bugs  would 
result  in  their  financial  ruin,  in  their  despondency  sought  relief  in 
suicide. 

When  we  take  into  consideration  that  the  financial  losses  as  above 
estimated  have  not  fallen  upon  the  entire  nation,  but  almost  without 
exception  upon  the  nine  States  previously  named  (see  Fig.  6)  it  will  be 
seen  that  this  diminutive  insect  constitutes  a  formidable  enemy  to  the 
agriculturist  of  these  States.  In  fact,  small  as  it  is,  this  pest  has  cost 
the  people  of  these  nine  States  a  sum  of  money  sufficient  to  defray  the 
entire  expense  of  the  National  Government  for  a  whole  year.  Fire 


Fig.  6.— Map  showing  areas  in  the  United  States  over  which  the  chinch  hug  occurs  in  most 
destructive  numhers  (author's  illustration). 


excepted,  there  is  probably  no  other  element  that  has  caused  such  an 
enormous  financial  loss  within  the  same  period  over  the  same  area  of 
country. 

NATURAL  CHECKS. 

All  adverse  natural  influences  alfecting  the  chinch  bug  will  be  treated 
under  this  head  with  the  exception  of  animal  and  vegetable  foes,  which 
are  considered  here  as  natural  enemies. 

INFLUENCE  OF  PRECIPITATION  ON  THE  CHINCH  BUG. 

There  is  probably  no  more  potent  factor  in  restraining  the  increase 
in  numbers  of  this  species  than  is  to  be  found  in  meteorological  influ- 
ences consequent  upon  rain.    The  fact  has  long  been  known  that  the 


32 


THE  CHINCH  BUG. 


years  of  greatest  abundance  of  the  chinch  bug  were  preceded  by  a 
series  of  years  during  which  there  had  been  a  deficiency  in  the  rainfall 
over  the  area  of  country  devastated  by  this  species.  In  fact,  it  has  in 
a  general  way  come  to  be  understood  that  dry  seasons  are  favorable 
and  wet  seasons  unfavorable  for  the  development  of  the  chinch  bug, 
though  the  details  of  the  phenomenon  have  never  been  very  carefully 


Fig.  7.— Map  showing  distribution  of  chinch  bug  in  Ohio  in  1896  (from  Bull.  Xo.  6,  n.  s.). 


and  elaborately  worked  out.  The  entomological  and  meteorological 
records  of  the  past  have,  however,  clearly  shown  that  the  amount  of 
the  annual  rainfall  is  not  a  safe  guide  in  this  problem.  Chinch  bugs 
have  occurred  in  excessive  numbers  during  years  of  heavy  precipitation. 

The  term  "wet  season,"  so  frequently  used  in  this:  connection,  is  an 
indefinite  one,  but  if  the  term  "season"  be  restricted  to  the  period  of 
time  intervening  between  the  vernal  and  autumnal  equinoxes  we  shall 


INFLUENCE  OF  PRECIPITATION. 


33 


have  more  definite  grounds  upon  which  to  base  our  studies  of  meteoro- 
logical influences.  Thus  applied,  the  terms  wet  or  dry  seasons  would 
include  within  them  the  two  breeding  periods  of  the  chinch  bug.  at  least 
largely  so,  north  of  latitude  30°  IS".  But  the  history  of  this  species  has 
shown  that  there  may  be  an  excess  of  rainfall  during  this  critical  period 
and  that  still  a  sufficient  number  of  insects  may  develop  to  work  serious 
injury  over  considerable  areas  of  country.    This  is  due  to  two,  and 


Fig.  8.— Map  showing  distribution  of  cbinch  bug  in  Obio  in  1897. 


perhaps  more,  causes.  In  the  first  place,  an  unusually  heavy  rainfall 
at  long  intervals,  while  bringing  up  the  total  for  a  given  period,  may 
have  but  little  effect  in  reducing  the  number  of  chinch  bugs,  while  even 
a  less  amount  of  precipitation  coming  at  short  intervals  and  in  the  midst 
of  the  hatehing  season  would  cause  a  far  greater  mortality  among  the 
young.  And,  in  the  second  place,  the  precipitation  may  come  at  the 
beginning  or  even  before  the  commencement  of  this  breeding  season  or 
5968— Xo.  15  3 


34 


THE  CHINCH  BUG. 


just  at  the  close  thereof,  thus  enabling  the  major  portion  of  the  young 
to  reach  a  period  in  their  development  wherein  they  are  little,  if  at  all, 
susceptible  to  the  effects  of  drenching  rains.  This  was  clearly  illus- 
trated in  southern  Ohio  during  the  spring  of  1896,  and  again  in  1897. 
Throughout  southern  Ohio,  in  1890,  between  latitude  38°  30'  and  39°  40', 
as  the  reports  of  the  United  States  Weather  Bureau  show,  there  had 


Fig.  9.— Map  showing  distribution  of  chinch  bug  in  Obio  in  1894  (from  Bull.  No.  6,  u.  s.). 


been  but  very  little  rain  up  to  May  11,  and  no  general  rain  until  May  25. 
The  effect  upon  the  young  bugs,  judging  from  the  destruction  which 
they  caused,  would  seem  to  have  been  to  destroy  only  the  latest  to 
hatch,  leaving  the  earlier  developing  young  sufficiently  advanced  to 
withstand  the  effects  of  the  later  and  heavier  rains.  The  accompany- 
ing map  (fig.  7)  will  show  the  areas  over  which  chinch  bugs  were 
reported  marked  thus  g,  while  the  area  seriously  ravaged  is  indicated 


INFLUENCE  OF  PRECIPITATION. 


35 


thus  #,  showing'  that  the  rain  came  too  late  in  such  a  section  to  ward 
off  an  outbreak  of  the  pest. 

According  to  the  Weather  Bureau  reports  also,  the  distribution  of 
rain  in  May,  1897,  differed  materially  from  that  of  the  same  month  of 
1896,  in  that  in  1897  the  major  portion  of  the  rain  fell  prior  to  the  15th, 
the  remainder  of  the  month  being  rather  dry,  the  only  general  precipi- 
tation occurring  on  the  23d  and  24th,  with  a  much  lighter  rain  on  the 


Fig.  10.— Map  showing  distribution  of  chinch  bug  in  Ohio  in  1895.  and  amount  of  precipitation  over 
the  State  during  May  of  the  same  year  (author's  illustration.) 


28th.  But  here  again  the  amount  was  insufficient  to  ward  off  serious 
njury,  as  is  indicated  by  map  (fig.  8),  the  same  symbols  being  used  here 
is  before.  In  this  case  it  was  probably  the  latter  portion  of  the  brood 
mat  survived,  as  a  personal  inspection  of  the  country  early  in  the 
nonth  failed  to  reveal  the  presence  of  young  bugs,  though  they  were 
jertainly  present  in  abundance  at  a  corresponding  period  of  the  pre- 
ceding year. 


36 


THE  CHINCH  BUG. 


That  the  amount  and  frequency  of  rain  during  the  month  of  May 
has  very  much  to  do  with  the  ravages  of  chinch  bugs  where  sufficient 
numbers  have  wintered  over  to  produce  the  requisite  number  of  young, 
is  further  shown  by  the  fact  that  in  1894  the  only  locality  where  serious 
ravages  were  committed  was  in  Wyandot  County,  as  shown  on  map 
|  fig,  9),  and  this  was  one  of  the  few  areas  in  Ohio  where  the  precipita- 
tion during  that  month  was  less  than  3  inches.  Except  over  a  circular 
area  covering  less  than  one  half  of  the  county  the  amount  of  precipita- 
tion was  3  to  5  inches,  and  this  area  includes  that  ravaged  by  the  chinch 
bugs  during  the  following  month. 

Still  more  striking,  however,  is  the  relation  between  the  two  phenomena 
during  the  following  year.  The  last  of  this  series  of  maps  (fig.  10)  shows 
the  area  over  which  chinch  bugs  were  reported  and  the  area  where  their 
injuries  were  the  most  severe;  also,  by  horizontal  lines,  the  areas  over 
which  the  amount  of  precipitation  was  the  least.  From  this  it  will  be 
observed  that  in  all  of  the  seriously  affected  area,  and  in  nearly  all  of  the 
area  over  which  the  pest  was  reported  at  all,  the  precipitation  during 
the  month  of  May,  1895,  was  from  1  to  2  inches,  the  extension  of  the 
point  westward  into  Shelby  County  being  especially  interesting'.  It 
may  be  said  with  regard  to  the  occurrences  outside  of  this  area  of  light 
precipitation  that  the  exact  localities  were  probably  not  indicated,  as 
the  information  was  secured  from  farmers,  and  their  locatious  as  indi- 
cated on  the  map  were  their  post-office  addresses,  which  might  have 
been  several  miles  away  in  any  direction,  and  the  isolated  points  of 
attack  were  often  based  upon  one  or  two  reports.  If  exact  localities 
could  have  been  obtained,  and  the  precise  area  of  precipitation  indi- 
cated, the  connection  between  the  two  phenomena  would  have  been 
shown  more  correctly,  and  would  probably  have  revealed  even  a  greater 
uniformity  than  is  now  apparent.  It  must  be  understood,  however,  that 
in  these  calculations  extreme  northeastern  Ohio  is  excluded,  and  I 
believe  that  what  is  true  of  the  balance  of  the  State  will  be  found  to  be 
equally  correct  as  regarding  territory  occupying  the  same  latitude  west- 
ward to  the  limit  of  this  area  of  distribution.  While  it  is  probable  that 
the  effect  of  precipitation  during  August  would  have  a  similar  influence 
on  the  second  brood  of  young,  and,  consequently,  upon  the  number  of 
adults  which  would  go  into  winter  quarters,  yet  a  careful  study  of  the 
two  factors  shows  that  meteorological  conditions  in  August  have  a  far 
less  influence  upon  the  following  brood  than  do  those  of  May. 

Owing  to  causes  which  are  as  yet  unknown  to  me  the  same  laws  do 
not  apply  to  the  northeastern  part  of  Ohio  and  to  what  I  have  termed 
the  west  bound  tide  of  migration.  Here  and  as  against  the  more  or 
less  short- winged  form  of  chinch  bug,  meteorological  conditions  appear 
v  to  exert  a  far  less  potent  influence.  What  is  true  of  meteorological 
conditions  during  May  elsewhere  in  Ohio,  seem  to  be  partly  true  of 
June  in  the  northeastern  portion  of  the  State,  though  there  is  not  the 
evidence  of  the  effect  of  precipitation  here  that  we  have  elsewhere. 


INFLUENCE  OF  PRECIPITATION. 


37 


Dr.  Lintner,  in  his  second  report,  while  discussing  the  outbreak  of 
chinch  bug  in  Xew  York  during  1882-83,  calls  attention  to  the  fact 
that  both  in  1881  and  1882  there  was  an  excess  of  precipitation.  On 
page  158  of  his  report  Dr.  Lintner  says  that  spring,  summer,  and  autumn 
were  exceptionally  wet.  In  spring  heavy  and  continued  rains  flooded 
meadows  which,  later,  showed  the  effect  of  chinch-bug  attack.  Even  at 
haying  time  while  the  bugs  were  young  and,  according  to  all  accounts, 
easily  killed  by  heavy  rains,  they  persisted  in  multiplying  and  living 
despite  the  fact  that  rains  were  so  frequent  and  severe  that  only  a 
portion  of  the  hay  could  be  gathered  in  a  proper  condition.  This  was 
the  state  of  affairs  on  July  5  when  the  hay  was  cut.  and  on  October  10 
Dr.  Lintner  stated  that  owing  to  continued  rains  grass  was  still  lying 
in  the  fields  and  could  not  be  gathered,  while  fields  of  oats  remained 
unharvested.  In  ail  of  the  reports  given  of  this  outbreak  it  was  stated 
that  the  damage  was  first  observed  in  August  or  September,  and  I 
believe  that  this  will  hold  good  as  applied  to  northeastern  Ohio. 

As  has  been  stated  the  females  oviposit  as  a  rule  at  or  just  below  the 
surface  of  the  ground,  and  the  young  make  their  way  upward  in  order 
to  secure  food.  In  case  of  cultivated  grains  this  mode  of  procedure  is 
absolutely  imperative,  as  the  bases  of  the  plants  are  at  that  time  too 
tough  and  woody  to  offer  sufficient  food.  But  in  the  case  of  timothy 
the  conditions  are  eutirely  different,  as  the  bulb  of  this  plaut,  situated 
just  below  the  surface  of  the  ground  and  convenient  to  the  place  of 
oviposition,  furnishes  an  ample  supply  of  food  without  making  it  nec- 
essary for  the  young  to  crawl  upward  in  order  to  secure  it.  Then,  too, 
the  surface  of  the  ground  in  cultivated  fields  is  nearly  or  quite  free  of 
dead  leaves  and  stems,  there  being  little  but  the  vertical-growing  plants 
to  afford  protection  from  the  weather.  In  timothy  meadows  the  sur- 
face of  the  ground  is  usually  covered  to  the  depth  of  an  inch  or  more 
with  dead  and  decaying  stubble  and  leaves,  and  the  top  of  the  ground 
itself  is  often  more  or  less  loose  and  mellow  in  the  immediate  proximity 
to  the  bulbs  of  the  plants.  It  would  appear  that  we  might  here  have 
a  partial  solution  of  the  problem  of  the  vital  effects  of  precipitation  on 
the  young  bugs.  Besides,  for  aught  we  know  the  progeny  of  this  quite 
short-winged  form  may  be  better  able  to  withstand  naturally  the  effect 
of  drenching  rains  than  that  of  the  east-bound  long-winged  form.  We 
must  recollect  that  in  the  one  case  the  progenitors  have  worked  their 
way  over  hot.  arid  plains  as  well  as  cool,  damp  prairies,  while  in  the 
other  case  the  tide  of  migration  lay  between  the  more  elevated  lands 
and  the  sandy  beaches  of  the  seashore  where  there  was  always  a  more 
or  less  near  proximity  to  the  ocean,  until  the  tide  of  migration  left  the 
seashore  and  drifted  westward  over  New  York  and  onward  into  north- 
eastern Ohio.    (See  map,  fig.  17.) 

This  influence  of  precipitation  on  the  young  chinch  bugs  while  in  the 
act  of  hatching,  and  that  of  temperature  upon  the  adults  in  winter,  are 
the  only  cases  where  meteorological  conditions  appear  to  have  a  direct 


38 


THE  CHINCH  BU(i. 


effect  on  this  species.  As  previously  shown,  the  temperature  effects 
are,  largely  at  least,  unfavorable  for  such  adults  as  may  happen  to  be 
more  or  less  unprotected  during-  the  hibernating  season.  Upon  this 
point  it  might  be  well  to  suggest  that  this  protection,  which  may  be 
composed  of  leaves  and  dried  grass,  may  be  burned  away  in  early 
winter  and  thus  leave  the  insects  without  the  expected  protective  cov- 
ering, or  this  covering  may  be  still  further  augmented  by  a  mantle  of 
snow,  which,  remaining  for  a  more  or  less  protracted  period  of  time, 
counteracts  the  influences  of  temperature,  and  the  latter  then  becomes 
a  factor  of  secondary  importance  in  the  problem  of  life  among  chinch 
ougs.  It  is  very  doubtful  if  temperature  is  as  vital  in  its  effects  as  are 
the  indirect  influences  of  precipitation  during  the  breeding  season. 

It  has  long  been  understood  that  the  two  species  of  entoinogenous 
fungi,  Sporotrichium  globuliferum  Speg.  and  Entomophthora  aphidis 
Hoffm.,  both  of  which  attack  the  chinch  bug,  require  for  their  rapid 
development  an  atmosphere  heavily  charged  with  moisture,  and  that 
without  this  neither  of  these  become  sufficiently  abundant  to  cause  any 
serious  mortality  among  the  insect  host,  but  this  matter  will  receive 
attention  in  the  discussion  of  these  parasitic  foes  further  on. 

INFLUENCE  OF  TEMPERATURE  OX  THE  CHINCH  BUG. 

I  would  like  to  call  attention  here  to  what  seems  to  me  a  possible 
influence  of  temperature  upon  what  I  have  termed  the  west-bound  tide 
of  migration.  When  the  time  arrives  for  the  hibernating  adults  to 
leave  their  winter  quarters  and  disperse  over  the  fields  prior  tooviposi- 
tion,  if  the  weather  should  prove  too  severe  they  have  but  to  remain  in 
these  quarters  a  while  longer  until  more  favorable  weather.  Thus  along 
the  northern  Atlantic  coast  the  season  is  generally  much  later  near  the 
shore  than  it  is  a  few  miles  inland,  and  Mr.  Schwarz*  has  called  atten- 
tion to  the  influence  which  this  phenomenon  exerts  upon-  the  chinch 
bug.  Xow,  this  retardation  amounts  to  about  a  month  in  spring,  I 
believe,  which  would  have  a  tendency  to  delay  oviposition,  especially 
among  the  short- winged  females.  If  this  were  continued  through  a 
long  period  of  time,  consequent  upon  the  slow  movement  of  this  tide 
of  migration  northward  along  the  coast,  it  would  hardly  be  surprising 
to  find  that  this  retarded  activity  in  spring  had  become  so  characteristic 
as  to  be  retained  after  this  tide  had  swept  to  the  westward,  and  resulted 
in  the  species  being  thus  single  brooded  in  the  East,  while  it  is  double 
brooded  in  the  east-bound  tide  of  migration  in  the  West.  This  effect  of 
a  long  habitation  along  the  shores  of  the  northern  Atlantic  would  be  to 
some  extent  encouraged  by  the  prolonged  northern  winter  and  the 
correspondingly  shorter  period  during  which  the  species  could  breed, 
and  thus  instead  of  the  effects  of  the  old  environment  becoming  oblit- 
erated they  might  be  continued,  or,  as  in  case  of  the  fore-shortening 
of  the  wings,  still  further  intensified.    If  the  effect  of  this  prolonged 


*  Insect  Life,  Vol.  VII,  p.  422. 


NATURAL  ENEMIES. 


39 


period  of  hibernation  has  been  to  reduce  the  number  of  broods,  then  it 
will  have  to  be  considered  as  a  natural  check,  in  that  to  a  certain  extent 
it  prevents  excessive  abundance  by  reducing  the  number  of  offspring. 
This  would  also  account  for  the  rather  surprising  immunity  that  has 
heretofore  been  enjoyed  by  the  northeastern  portion  of  the  country 
from  the  ravages  of  this  destructive  species. 

NATURAL  ENEMIES. 

It  is  possible  that  there  are  some  reasons  which  might  appear  to 
justify  the  placing  of  fungous  enemies  of  the  °,biucii  bug  among  the 
natural  checks,  as  they  no  doubt  do  exert  a  more  or  less  powerful 
influence  in  that  direction,  but  it  seems  more  convenient  to  include 
them  among  natural  enemies,  especially  as  one  at  least  has  come  to  be 
applied  artificially  to  overcome  the  insect.  The  fact  that  the  abundance, 
and  consequent  influence,  of  these  fungous  enemies  is  almost  entirely 
dependent  upon  meteorological  conditions  is  sufficient  to  place  them  in 
a  secondary  position,  even  though  they  may  under  favorable  meteor- 
ological conditions  act  as  natural  checks.  All,  doubtless,  have  other 
host  insects,  and  the  two  most  important  have  been  known  to  break 
out  again,  and  again  spontaneously  and  destroy  myriads  of  chinch 
bugs  when  the  latter  were  present  in  excessive  numbers.  But  this  has 
taken  place  only  in  connection  with  the  necessary  precipitation ;  hence 
these  fungi  become  natural  enemies  only  under  certain  favorable  weather 
conditions;  and  while  their  season  of  most  potent  effect  is  during  the 
time  when  the  chinch  bug  is  developing  from  the  egg  to  the  adult,  yet  as 
shown  by  observation  they  may  exert  powerful  and  fatal  effects  among 
the  adults,  where  these  last  have  congregated  together  in  masses. 

PARASITIC  FUNGI. 

The  two  species  of  entomogenous  fungi  to  which  reference  has  just 
been  made  are  Entomophthora  aphidis  Hoffman*  and  Sporotrichium 
globuliferum  Speg,t  both  having  probably  been  associated  in  destroy- 
ing the  chinch  bug  spontaneously  in  the  fields,  and  doubtless  were 
distributed  to  correspondents  by  Professor  Snow  and  others  to  be 
artificially  established  in  fields  where  there  was  an  overabundance  of 
chinch  bugs.  For  this  reason  it  is  impossible  to  separate  the  two,  even 
the  first  observations  of  Dr.  Henry  Shinier  t  probably  applying  to  their 
joint  effect. 

Dr.  Shinier,  however,  was  the  first  to  call  attention  to  the  widespread 
and  fatal  effects  of  fungous  diseases  among  chinch  bugs,  and  while  his 
explanations  therefor  seem  now  crude  and  illogical,  his  observations 
were  made  with  such  care  and  accuracy  that  we  have  not  yet  had  occa- 
sion to  materially  revise  them,  though  his  conclusions  have  been  shown 

*  Hoffman,  in  Fresenius's    Eutomophthorea1/'  p.  208,  figs.  5lJ-67. 
tSpegazzini,  " Fungi  Argentini,"  II.  p.  42. 
X  Proc.  Acad.  Nat.  Sci.  Phila.,  May.  1SG7. 


40 


THE  CHINCH  BUG. 


to  have  been  incorrect.  Under  date  of  July  10,  1865,  he  makes  this 
observation.  *  *  *  "I  found  many  dying  on  the  low  creek-bottom 
land  from  the  effects  of  some  disease,  while  they  are  yet  in  the  larva? 
state — a  remarkable  and  rare  phenomenon  for  insects  thus  in  such  a 
wholesale  manner  to  be  dying  without  attaining  their  maturity,  and  no 
insect  enemy  or  other  efficient  cause  to  be  observed  capable  of  pro- 
ducing this  important  result."  Again,  under  date  of  July  22:  "On 
low  grounds  the  chinch  bugs  are  dead  from  the  disease  above  alluded 
to,  and  the  same  disease  is  spreading  to  the  hills  and  high  prairies." 

Under  this  date  also  he  speaks  of  the  very  wet  weather,  and  states 
that  in  a  barley  field  the  chinch  bugs  began  to  die  at  about  the  same 
time  that  they  did  on  the  low  creek  bottom,  and  that  they  rapidly  met 
the  same  fate,  so  that  few  of  them  lived  to  find  their  way  to  a  neigh- 
boring cornfield,  while  under  date  of  August  8  he  states  that  of  those 
that  migrated  to  the  cornfields  "very  few  are  to  be  found  remaining 
alive;  but  the  ground  around  the  base  of  the  cornhills  is  almost  literally 
covered  with  their  mouldering,  decomposing  dead  bodies.  They  are 
dead  everywhere,  not  lying  on  the  ground  alone,  but  sticking  to  the 
blades  and  stalks  of  corn  in  great  numbers,  in  all  stages  of  develop- 
ment, larva,  pupa,  and  imago." 

"This  disease  among  the  chinch  bugs  was  associated  with  the  long- 
continued  wet,  cloudy,  cool  weather  that  prevailed  during  a  greater 
portion  of  the  period  of  their  development."    *    *  * 

These  are  precisely  the  conditions  under  which  these  fungi  have 
been  observed  to  prove  the  most  fatal  to  the  chinch  bug  during  recent 
years,  where  their  introduction  among  the  host  insects  was  accom- 
plished by  artificial  means.  While  Dr.  Shimer  probably  never  antici- 
pated the  artificial  cultivation  of  his  "disease,"  and  the  results  which 
have  since  been  obtained  from  its  artificial  dissemination  in  the  fields, 
yet  his  careful  and  painstaking  studies  must  ever  be  associated  with 
the  application  of  fungous  diseases  in  the  destruction  of  insects  in 
America.  It  is  certainly  to  be  regretted  that  such  practical  entomol- 
ogists as  Mr.  B.  D.  Walsh  and  Dr.  0.  V.  Riley  should  have  expressed 
themselves  so  discouragingly  regarding  Dr.  Shimer's  observations  and 
conclusions,  Dr.  Riley,  so  late  as  1870,  even  going  so  far  as  to  ridicule 
the  theory  of  disease  being  in  anyway  responsible  for  the  death  of  the 
chinch  bugs  observed  by  Dr.  Shimer.* 

It  was  not  until  1879  that  an  entomologist  came  to  the  rescue  of  Dr. 
Shimer's  theory  of  disease  among  chinch  bugs.  Dr.  Cyrus  Thomas,  in 
his  Bulletin  No.  5,  of  the  United  States  Entomological  Commission, 
1879,  page  24,  stated  that  while  Dr.  Shimer's  plague  among  chinch 
bugs  was  somewhat  extraordinary,  yet  it  was  in  accordance  with  facts 
that  he  had  himself  ascertained  iu  reference  to  other  insects,  and,  in 
proof,  cited  a  similar  wholesale  destruction  of  flies  in  southwestern 
Virginia  and  eastern  Tennessee  in  the  year  1849,  and  also  a  similar 

*  Second  Keport  State  Entomologist  of  Missouri,  pp.  24-25,  1870. 


FUNGOUS  ENEMIES. 


41 


epidemic  among  grasshoppers  in  western  Minnesota,  Dakota,  and  north- 
ern Iowa  in  1872.  This  position  of  Dr.  Thomas  in  support  of  Dr. 
Shinier  may  be  regarded  as  a  second  step  in  our  advance  in  a  knowl- 
edge of  the  influence  of  meteorological  conditions  on  the  chinch  bug. 
It  paved  the  way  for  further  research  in  this  direction. 

Fungous  enemies  of  the  chinch  bug  determined. — While  the  subject  of 
epidemic  and  contagious  diseases  of  insects  was  discussed  to  a  greater 
or  less  extent  among  scientific  men,  there  was  a  decided  lack  of  actual 
experimentation,  and  none  at  all  with  the  fungous  parasites  of  the 
chinch  bug  until  18S2  and  1883,  when  Prof.  S.  A.  Forbes  began  what 
ultimately  proved  to  be  a  long  series  of  studies  of  the  chinch  bug  and  its 
natural  enemies.  At  this  time,  1882.  Professor  Forbes  was  more  espe- 
cially interested  in  the  bacterial  diseases  of  the  chinch  bug,  and  though 
he  found,  at  Jacksonville,  111.,  many  specimens  of  dead  chinch  bugs 
embedded  in  a  dense  mat  of  white  fungous  threads,  which  sometimes 
almost  hid  the  body  and  reminded  him  of  the  fatal  disease  previously 
reported  by  Dr.  Shinier,  yet  except  to  secure  from  Prof.  T.  J.  Burrill  a 
determination  of  this  fungus  as  belonging  to  the  Entomophthora  no 
progress  was  made  in  the  study  of  this  particular  phase  of  the  chinch- 
bug  problem.* 

In  July,  1887,  Professor  Forbes  found  a  second  fungus  attacking  the 
chinch  bug  in  Clinton  County.  111.,  and  which  he  determined  as  belonging 
to  the  genus  Botrytus.  but  this  conclusion  has  since  been  revised  and 
the  species  is  now  known  as  Sporotrichium  globuliferum  Speg.  This 
discovery  of  a  second  species  of  entomogenous  fungi  and  its  separation 
from  the  Entomophthora,  comprises  what  maybe  justly  termed  a  third 
step  in  the  advancement  of  our  knowledge  of  this  problem.  Professor 
Forbes,  however,  seems  to  have  still  been  too  deeply  interested  in  his 
bacterial  studies  to  pay  any  special  attention  to  the  other  phases  of 
his  problem,  further  than  to  record  the  occurrence  of  his  new  Botrytus 
in  various  localities  in  Illinois,  and  in  one  instance  on  a  beetle.  Parandra 
brunnea  observed  by  Mr.  John  Marten,  at  Champaign),  and,  similarly, 
to  note  the  occurrence  of  the  still  specifically  undetermined  Entomoph- 
thora. t 

The  scene  of  action  now  changes  from  Illinois  to  Kansas,  and  to  Prof. 
F.  H.  Snow  belongs  the  credit  of  first  applying  the  knowledge  that 
had  been  gained  up  to  that  time  (1889)  by  confining  supposed  healthy 
chinch  bugs  with  others  affected  by  either  one  or  the  other  of  the 
fungi,  or  possibly  both  Entomophthora  and  Sporotrichium,  and  using 
the  bugs  thus  infected  for  the  propagation,  in  the  field,  of  the  disease 
from  which  they  had  died. 

As  early  as  1887-88  Professor  Snow  expressed,  in  the  Sixth  Biennial 
Beport  of  the  Kansas  State  Board  of  Agriculture,  the  opinion  that  "in 
the  warfare  of  man  against  his  insect  foes  a  most  valuable  ally  will  be 

*  Twelfth  report  of  the  State  Entomologist  of  Illinois,  pp.  47-51,  1882. 
t  Sixteenth  Report  of  State  Entomologist  of  Illinois,  pp.  46-49,  18^8. 


42 


THE  CHINCH  BUG. 


found  in  the  bacterial  and  fungoid  diseases  which  may  be  artificially 
introduced  when  nature  fails  to  come  to  our  aid,"  an  opinion  at  that 
time  largely  based  upon  the  investigations  of  Professor  Forbes  and 
his  own  observations  of  the  chinch  bug  in  Kansas,  thus  paving  the 
way  for  the  experiments  of  1889.  Professor  Snow  had  now  obtained  a 
specific  determination  of  the  fungous  disease  as  (Empusa)  Entomoph- 
thora  aphidis  Hoffman,  although  there  is  some  ground  for  the  suspi- 
cion that  Sporotrichium  globuliferum  was  also  present. 

Entomophthora  aphidis  was  already  known  to  affect  hemiptera  in 
Germany  and  the  United  States.  Dr.  Koland  Thaxter  states  that,  as 
early  as  1886,  his  attention  had  been  called  to  the  attacks  of  this  fun- 
gus on  aphides  in  the  greenhouses  at  Cambridge,  Mass.,  where  it  acted 
as  a  decided  check,  and  later,  in  1887,  Dr.  L.  O.  Howard  had  called  his 
attention  to  great  quantities  of  aphides  dying  with  the  same  disease 
on  clover  near  the  Agricultural  Department  buildings  in  Washington, 
D.  C* 

Field  and  laboratory  experiments  in  Indiana. — On  July  20,  1889,  the 
writer,  at  that  time  a  special  agent  of  the  Division  of  Entomology  of 
the  United  States  Department  of  Agriculture,  stationed  at  Lafayette, 
Ind.,  received,  through  the  kindness  of  Professor  Snow,  enough  mate- 
rial with  which  to  make  some  experiments,  the  chinch  bug  being  at 
that  time  very  abundant  at  Lafayette,  and  an  exceptionally  good 
opportunity  thus  being  offered  for  experimentation.  The  results  of 
these  experiments  were  published  in  detail  in  Bulletin  22,  United 
States  Department  of  Agriculture,  Division  of  Entomology  (pp.  55-63), 
but  as  this  was  the  first  series  of  experiments  carried  out  with  a  view 
of  testing  with  exactness  the  precise  effects  of  varying  degrees  of  tem- 
perature and  atmospheric  moisture  on  the  growth  of  the  Entomoph- 
thora, and  carefully  following  out  the  progress  of  the  disease  under 
varying  meteorological  conditions,  the  matter  is  here  republished  in 
full,  the  bulletin  in  which  it  was  originally  included  being  now  out  of 
print. 

These  diseased  bugs  were  placed  under  glass  with  living  ones  from  the  fields,  the 
latter  being  provided  with  food  and  kept  thus  confined  for  fifty-three  hours,  when 
the  major  portion  of  them  were  placed  on  several  hills  of  corn  seriously  infested  by 
bugs,  the  remainder  with  the  dried  remains  received  from  Professor  Snow  being 
scattered  about  over  a  small  area  of  young  wheat  sown  for  experiment  and  also 
swarming  with  young  chinch  bugs.  The  hills  of  corn  on  which  the  bugs  had  been 
placed  were  isolated  from  others,  equally  badly  infested,  by  narrow  frames  of  boards 
placed  on  the  ground  and  the  upper  edges  covered  with  tar.  This  last  precaution 
was  taken  in  order  to  prevent  communication  with  other  hills,  intended  as  checks  on 
those  used  directly  in  the  experiment.  The  area  of  young  wheat  over  which  infested 
bugs  had  been  placed  was  not  inclosed,  but  its  limits  carefully  marked.  Five  days 
after,  July  27,  a  single  bug  was  found  on  one  of  the  isolated  hills  of  corn  which  had 
very  evidently  died  from  the  effects  of  Entomophthora,  and  by  the  30th  enough 
others  were  found  to  show  that  the  fungus  had  fully  established  itself  and  the  bar- 
riers about  the  isolated  hills  were  removed.    On  August  2,  dead  bugs  covered  with 

*Meinoir8  of  the  Boston  Society  of  Natural  History,  Vol.  IV,  p.  176. 


FIELD  AND  LABORATORY  EXPERIMENTS  IN  INDIA.  43 


Entomophthora  were  found  in  considerable  numbers  about  hills  of  corn  25  feet  from 
where  the  original  colonies  had  been  placed  and  also  throughout  and  even  55  feet 
beyond  the  area  of  young  wheat  over  which  dead  and  affected  bugs  had  been  dis- 
tributed. Daily  observations  were  now  made,  but  the  progress  of  the  disease  seemed 
to  come  to  a  standstill.  From  the  5th  of  August  up  to  the  9th  it  was  almost  impos- 
sible to  get  sufficient  material,  outside,  to  enable  me  to  carry  on  laboratory  experi- 
ments. August  13  the  spread  of  Entomophthora  appeared  to  have  taken  on  new 
life,  and  diseased  bugs  were  becoming  much  more  numerous.  August  15  found 
diseased  bugs  172  feet  from  any  place  where  they  had  been  previously  observed. 
August  20,  diseased  bugs  were  very  abundant  over  all  of  the  area  where  disease  had 
been  distributed,  and  two  days  later  examples  were  found  a  quarter  of  a  mile  from 
the  starting  point  of  the  disease.  Immediately  after  this,  however,  another  halt, 
both  in  the  intensity  of  attack  and  rapidity  with  which  it  spread,  due  either  to  the 
dry  weather  or  to  the  tact  that  the  bugs  had  now  all  reached  the  adult  stage  and 
had  become  diffused  over  the  country,  no  longer  congregating  together.  From  either 
one  or  the  other,  or  both  of  these  causes,  I  lost  track  of  the  Entomophthora  and  was 
not  able  to  again  find  it  in  the  fields.  It  seems  proper  to  state  here  that  chinch  bugs 
were  not  at  any  time  excessively  abundant.  The  greatest  numbers  were  in  the  exact 
localities  where  the  disease  was  first  distributed,  the  congregating  at  these  places 
being  brought  about  by  the  close  proximity  to  a  large  number  of  small  experimental 
plats  of  wheat,  and  when  this  was  harvested  the  bugs  collected  <  //  masse  on  the  corn 
and  young  wheat.  In  connection  with  these  facts,  it  is  also  interesting  to  note  that 
from  July  15  to  August  31  there  were  ten  days  on  which  rain  fell.  The  dates  of  these 
rains  and  the  amount  of  precipitation  is  given  below : 


Date  Precipi-  Date  Precipi- 

mte-  tation.  1,lte-  tation. 


Inches.  Inches. 

July  17                                                           0.02     July  29  .  0.78 

19                                                           1.25  !          30   .50 

22                                                            .20  ;  Aug.  9  i  3.36 

23                                                            .04  I          13   .15 

26                                                            .13            14  1  .02 


With  a  view  of  learning  whether  or  not  there  was  any  difference  as  regards  sus- 
ceptibility to  the  attack  of  Entomophthora,  between  bugs  in  different  stages  of 
development,  a  series  of  experiments  was  begun,  as  follows : 

Young  plants  of  Setaria  glauca  were  transplanted  to  a  box.  and  upon  each  plant 
was  placed  a  dead  bug  covered  with  the  fungus,  and  also  healthy  larva1 :  larva'  just 
on  the  point  of  pupation ;  pupae  just  prior  to  reaching  the  adult  stage,  and  fully 
developed  adults,  each  stage  being  placed  on  separate  plants,  and  each  covered  with 
a  small  inverted  glass  vial  designated  by  lettering.  As  checks,  another  series  was 
prepared,  like  the  first  in  every  particular.  The  soil  hi  the  box  was  kept  well 
moistened,  and  the  plants  remained  fresh.  This  experiment  was  made  on  August  2, 
about  the  time  when  the  attack  outside  began  to  diminish  in  intensity.  The  follow- 
ing are  the  results  of  examinations  on  the  dates  indicated,  the  original  experiments 
being  indicated  by  capitals  and  the  checks  by  small  letters,  thus — A-a.  adult;  B-b, 
young  larva1 ;  C-e,  older  larva1 ;  D-d,  pupa1. 


Date. 

A.  a. 

B. 

h. 

C. 

c. 

D. 

d. 

Aus.  5 
Aug.  6 
Aug.  7 
Aug.  16, 

Healthy  . . 

1  dead  

All  dead  . . 
All  dead.. 

Healthy  . . 
1  dead  . . . . 
3  dead  .... 
All  dead . . 

Healthv  . 
Healthy  - 
3  dead  *. . . 
All  dead  . 

Healthy  . 
Healthy 
1  dead  . . . 
All  dead  . 

1  dead  . . . 
1  dead  . . . 
3  dead  ... 
All  dead . 

Healthy  - 
Healthy  . 
1  dead  . . . 

1  dead  . . . 
:i  dead  . . . 

1  dead. 
1  dead. 
5  dead. 
All  dead. 

All  dead . 

All  dead  . 

On  the  same  day  this  experiment  was  begun  a  second  was  also  commenced,  like 
the  first  in  every  particular,  except  that  the  healthy  bugs  used  in  experimentation 


44 


THE  CHINCH  BUG. 


were  exposed  to  fungus-infected  individuals  for  only  live  hours  and  then  placed 
under  their  respective  glasses.  As  a  result,  on  August  15,  thirteen  days  after,  none 
had  died)  thus  strongly  indicating  that  the  Entomophthora  did  not  exist  generally 
in  the  fields,  and  that  it  could  not  he  communicated  during  a  period  of  five  hours' 
exposure. 

On  August  7  a  large  numher  of  healthy  hugs  were  placed  under  glass,  with  a 
number  which  had  recently  died  from  Entomophthora,  the  moisture  in  the  vessel 
being  absorbed  by  calcium  chloride.  A  check  experiment  was  also  commenced, 
where  the  material  and  the  conditions  were  the  same,  except  the  humidity  of  the 
atmosphere,  care  being  taken  to  have  the  latter  as  nearly  saturated  with  moisture 
as  possible.  August  10,  the  original  experiment  was  divided  and  a  portion  of  the 
healthy  bugs  removed  and  placed  in  a  damp  environment,  the  remainder  being  kept 
under  the  original  dry  conditions.  The  results  on  August  22  were  as  follows:  In 
the  original  experiment,  where  the  healthy  bugs  had  been  continually  in  dry 
quarters,  not  a  single  bug  had  died  from  Entomophthora.  Not  only  this,  but  none 
of  those  which  had  been  removed  after  three  days  and  placed  in  dry  quarters  had 
died,  showing  that  the  disease  was  not  contracted  and  did  not  develop  in  healthy 
bugs,  though  kept  exposed  in  a  dry  atmosphere  for  fifteen  days,  nor  could  it  be 
originated  by  placing,  in  a  damp  atmosphere,  for  twelve  days,  bugs  which  had  been 
exposed  to  contagion  for  three  days  in  dry  quarters.  The  results  with  the  check 
experiment  were  quite  different.  Within  five  days  after  being  confined  with 
the  Entomophthora,  the  healthy  bugs  began  to  die  from  effects  of  the  disease,  and 
in  three  days  more  every  one  had  died  from  the  same  cause,  their  bodies  being 
covered  with  spores. 

Still  another  experiment  was  tried  which  consisted  in  confining  a  large  number 
of  healthy  bugs  with  others  diseased  in  a  damp  environment,  and  when  the  fungus 
had  destroyed  a  portion  the  remainder  were  divided  and  a  part  removed  to  dry 
quarters.  The  result  was  that  while  those  left  in  damp  confinement  continued  to 
die,  none  of  those  inclosed  in  dry  environment  were  destroyed.  As  the  fungus  had 
by  this  time  become  distributed  over  the  experiment  farm  so  that  I  could  not  tell 
with  certainty  whether  material  from  the  fields  was  in  a  perfectly  healthy  condition 
or  not,  no  further  experiments  were  made  in  this  direction. 

From  the  foregoing  it  will  be  observed  that  the  essential  element  in  all  of  these 
experiments  was  an  abundance  of  moisture,  without  which  the  Entomophthora 
could  neither  become  established  nor  flourish  after  it  had  gained  a  footing.  Again, 
the  extent  to  which  the  disease  will  prove  contagious  will  depend  upon  the  number 
of  bugs.  Without  great  numbers  massed  together  comparatively  few  would  con- 
tract the  disease.  To  sum  up  the  matter,  there  is  little  hope  for  relief  to  the  farmer 
from  the  influence  of  Entomophthora,  except  when  chinch  bugs  are  abundant  and 
massed  together  in  great  numbers,  and  during  a  period  of  wet  weather.  I  have  suc- 
ceeded in  getting  the  fungus  established  at  two  widely  located  points  in  Indiana, 
and  do  not  consider  it  at  all  difficult  to  introduce  in  localities  where  chinch  bugs 
are  abundant,  provided  the  weather  is  favorable.  But  if  it  is  ever  utilized  by  the 
farmer,  which  seems  to  me  to  be  at  present  a  matter  of  considerable  doubt,  it  will 
only  be  after  the  pest  has  become  very  abundant,  during  the  time  between  the  first 
larval  and  adult  stages  and  in  a  wet  time.  After  the  Entomophthora  has  been  intro- 
duced into  a  certain  field  it  will  become  diffused  only  in  proportion  as  the  bugs 
travel  about  and  healthy  bugs  come  in  contact  with  spores  from  those  which  have 
died  from  the  disease.    This  will  not  be  very  great  until  the  pupal  stage  is  reached. 

The  larva?  of  chinch  bugs  seem  to  in  some  way  understand  that  while  molting 
they  will  be  well  nigh  helpless,  and  heuce  hide  themselves  away  in  vast  numbers  in 
secluded  places.  Under  such  conditions  the  spores  thrown  from  diseased  bugs  would 
reach  a  larger  number  of  their  fellows.  I  have  found  adults  but  recently  molted 
affected  by  the  Entomophthora.  After  the  bugs  acquire  wings  and  scatter  them- 
selves over  the  country,  the  liability  to  contagion  will  be  again  reduced,  unless  in 
case  of  very  severe  invasions,  where,  from  force  of  numbers,  congregating  on  or  about 
food  jdants  becomes  a  necessity.    Hence,  the  introduction  of  the  fungus  among 


FIRST  FIELD  APPLICATIONS  OF  FUNGOUS  ENEMIES. 


45 


larva3  will  at  first  proceed  but  slowly,  and  only  in  extreme  cases  and  under  favor- 
able conditions  can  it  be  expected  to  proceed  much  more  rapidly  among  adult  bugs. 
In  short,  the  only  way  that  this  fungoid  disease  seems  capable  of  being  employed  in 
agriculture  is  by  the  establishment  of  some  central  propagating  station  to  which 
farmers  can  apply  and  receive  an  abundant  supply  of  infected  bugs  on  short  notice. 
By  this  means  they  could  take  advantage  of  a  rainy  period  of  a  week  or  ten  days, 
and,  if  they  can  contrive  by  sowing  plats  of  millet  and  Hungarian  to  mass  the  bugs 
in  certain  localities  about  their  fields,  they  might  accomplish  something  toward 
warding  off  an  invasion.  But  the  possibility  of  overcoming  an  iuvasion  after  it  is 
fully  under  way,  as  is  almost  sure  to  be  the  case  during  a  dry  season,  it  must  be 
confessed  is  not  very  encouraging.  My  failure  after  repeated  experiments  to  pro- 
duce this  Entomophthora  in  the  vicinity  of  Lafayette  without  the  importation  of 
germs  is  decidedly  against  the  theory  tnat  might  be  advanced  that  the  northeastern 
portion  of  the  State  was  kept  free  of  destructive  invasions  by  reason  of  this  disease 
brought  about  by  wet  weather.  There  is  as  yet  no  reason  to  believe  that  the  disease 
has  ever  existed  in  that  section  of  the  State. 

The  fungus  with  which  I  had  been  experimenting  was  determined  for 
me  as  an  Entomopthora  by  Dr.  J.  0.  Arthur,  and  the  probability  is  that 
it  was  E.  aphidis,  though  it  is  possible  that  Sporotrichium  was  also 
preseut  and  remained  unobserved  by  me. 

First  field  applications  of  fungous  enemies  of  the  chinch  bug. — I  have 
stated  that  the  credit  of  first  confining  healthy  chinch  bugs  with  those 
diseased  and  utilizing  the  thus  infected  individuals  by  transporting 
them  to  sections  of  the  country  supposedly  free  from  the  disease  in 
order  to  create  new  areas  of  infection,  belonged  to  Prof.  F.  H.  Snow. 
During  October,  1888,  the  year  prior  to  that  during  which  Professor 
Snow  began  his  experiments,  Prof.  Otto  Lugger,  of  Minnesota,  collected 
a  quantity  of  diseased  chinch  bugs  at  the  experiment  station  at  St. 
Anthouy  Park  and  distributed  them  to  eighteen  different  localities  in 
the  southern  part  of  the  State  where  the  pest  was  known  to  occur  in 
destructive  abundance.  The  diseased  material  was  sent  out  in  tin 
boxes  by  mail,  and  the  contents  of  the  boxes,  on  arrival  at  their  desti- 
nation, were  simply  thrown  in  any  field  where  there  was  an  abundance 
of  chinch  bugs.  Later  in  the  season  the  condition  of  affairs  where 
these  distributions  had  been  made  was  such  that  "careful  search  in 
the  majority  of  places  failed  to  produce  a  single  living  specimen,  while 
the  traces  of  the  disease  were  found  everywhere."  With  a  spirit  of 
caution  and  exactness  in  every  way  most  commendable  on  the  part  of 
Professor  Lugger,  he  says:  "The  disease  spread  so  rapidly  that  even 
corn  growing  near  wheat  fields  crowded  with  chinch  bugs  was  entirely 
protected,  and  no  bugs  had  entered  it  in  all  the  places  visited  by  myself. 
But  I  am  by  no  means  satisfied  that  the  disease  was  really  introduced 
in  this  manner.  Is  it  not  possible  that  the  disease  was  already  there, 
unknown  to  anyone,  and  that  I  had  simply  reintroduced  its  germs? 
The  reason  for  this  belief  is  based  upon  the  fact  that  too  large  an  area 
was  infested  by  the  disease — too  large  to  be  readily  accounted  for  by 
the  short  time  in  which  the  atmospheric  conditions  were  apparently 
in  its  favor."  * 


*  University  of  Minnesota  Experiment  Sta.,  Bull.  4,  Oct.,  1888,  pp.  40-41. 


46 


THE  CHINCH  BUG. 


In  this  case  Professor  Lugger  states  that  both  Entoinophthora  aud 
Sporotrichium  were  present  and  the  latter  was  sent  by  him  to  Professor 
Forbes,  so  there  is  the  same  confusion  of  the  two  fungi  in  this  case  that 
existed  in  my  own  experiments  in  Indiana,  except  that  in  the  one  case 
it  was  certain  that  Entomophthora  was  present,  while  in  the  other  it 
was  the  Sporotrichium. 

The  work  of  Professor  Snow  in  Kansas. — While  Professor  Snow  had 
the  experience  and  observations  of  Shinier,  Forbes,  and  Lugger  to  aid 
him  in  his  first  efforts  to  apply  the  knowledge  gained  by  these  gentle- 
men, yet  it  must  be  said  that  it  has  been  largely  due  to  his  untiring 
energy  and  perseverance  that  the  use  of  these  fungi  has  reached  the 
present  state  of  importance.  It  will  hardly  be  saying  too  much  if  we 
state  that  his  persistent  undaunted  labors,  in  the  face  of  much  skepti- 
cism and  opposition,  has  vron  for  him  the  admiration  of  his  fellow- 
workers,  even  among  those  who  were  long  in  extreme  doubt  as  to  the 
success  of  his  labor.  He  has  done  more  than  any  other  one  person  to 
call  attention  to  the  possibilities  of  practical  benefits  to  be  derived  by 
farmers  themselves;  has  done  more  to  advertise  the  merits  of  these 
fungous  diseases  among  the  masses  than  any  one  else,  and,  in  fact,  has 
made  the  "  chinch-bug  fungus  "  almost  a  household  word  over  the  entire 
United  States. 

It  is  therefore  all  the  more  to  be  lamented  that  he  should  have 
accepted  and  published  in  his  several  reports  the  unsubstantiated 
statements  of  farmers  whose  testimony  on  a  matter  of  this  nature  is, 
as  every  entomologist  knows,  absolutely  worthless  unless  accompanied 
by  specimens.  From  my  own  personal  experience  in  this  direction  and 
in  several  States  I  have  long  ago  disregarded  all  reports  relating  to 
the  efficiency  or  inefficiency  of  these  fungous  diseases  among  chinch 
bugs,  when  such  came  from  the  ordinary  farmer  without  being  accom- 
panied by  specimens  for  examination.  The  cast  pupal  skins  of  the 
chinch  bug  pass  with  nonentomologists  very  well  for  dead  bugs,  and  if 
the  former  have  been  attacked  by  the  ordinary  white  molds  the  decep- 
tion, except  to  the  eye  of  an  expert,  is  complete. 

It  is  with  extreme  reluctance  and  with  anything  but  ill  will  toward 
Professor  Snow  that  his  voluminous  reports  on  the  u  Contagious  dis- 
eases of  the  chinch  bug'1  have  been  cast  aside  as  quite  worthless  and 
only  his  laboratory  experiments  accepted.  He  has,  no  doubt,  accom- 
plished much  in  his  State  toward  assisting  the  agriculturist  in  fighting 
the  chinch  bug,  but  much  is  left  for  others  to  prove  by  the  care  and 
caution  that  should  have  characterized  his  own  work  and  conclusions. 
There  is  probably  not  an  entomologist  who  has  used  these  fungous  dis- 
eases to  distribute  among  farmers  who  has  not  found  just  such  condi- 
tions as  did  Professor  Lugger,  in  Minnesota,  where  it  was  impossible 
to  determine  whether  these  diseases  had  been  introduced  artificially 
or  whether  they  were  already  present  and  had  been  overlooked.  In 
my  own  experience,  while  receiving  chinch  bugs  from  different  parts  of 


USE  OF  SPOROTRICHIUM  GLOBULIFERUM. 


47 


Ohio  to  be  infected  with"  the  disease,  consignments  liave  come  to  me 
with  the  insects  dying  and  others  dead  and  covered  with  Sporotrichiuni, 
showing  that  this  was  already  present  and  that  the  very  utmost  that 
we  could  expect  to  accomplish  would  be  to  aid  in  locally  spreading  the 
contagion.  Besides  this,  I  have  sent  material  to  farmers  sufficient  to 
start  the  fungus  in  their  fields,  knowing  perfectly  well  that  it  would  be 
a  considerable  time  before  actual  benefits  could  by  any  possibility  be 
expected  to  materialize,  and  within  a  week  received  the  astonishing 
information  that  the  fungus  was  so  perfectly  successful  that  the  bugs 
all  disappeared  within  a  few  days  after  the  application  of  the  disease. 
I  have  no  doubt  but  that  the  distribution  of  upward  of  7,000  boxes  of 
these  fungi  to  the  farmers  of  Kansas  has  accomplished  a  vast  amount 
of  good,  but  beyond  this  it  is  impossible  to  go.  Of  Professor  Snow's 
laboratory  work  or  the  labors  of  himself  and  assistants  in  the  fields  no 
criticisms  can  be  made,  and  I  shall  have  occasion  to  quote  from  these 
in  future  pages  of  this  bulletin. 

Sporot  rich  turn  globuUferum,  or  at  any  rate  the  fungus  which  is  now 
passing  under  that  name,  was  first  found  by  Professor  Forbes  to  infest 
the  chinch  bug  in  Illinois  in  1887,  and  its  destructive  effects  observed 
in  the  fields  in  the  autumn  of  1888. 

Since  the  last-mentioned  date  I  have  distributed  upward  of  3,000 
packages  of  this  fungus  to  the  farmers  of  Ohio  during  the  outbreak  of 
chinch  bug  in  the  State  in  1895,  1896,  and  1897,  and  know  from  per- 
sonal observation  and  study  that  it  is  under  certain  favorable  condi- 
tions a  deadly  foe  of  this  species,  that  its  use  under  these  conditions  is 
practical,  and  that  if  its  application  can  be  made  simultaneously  with 
the  commencement  of  the  breeding  season  it  will  prove  effectual.  This 
statement  is  made  for  the  reason  that  so  late  as  1895  Dr.  M.  C.  Cook, 
in  his  popular  work  on  entomogenous  fungi,  "Vegetable  Wasps  and 
Plant  Worms"  (p.  120),  states  that  "no  species  of  this  genus  is  known 
to  have  occurred  on  living  matter  as  they  are  saprophytes  pure  and 
simple,  and  then,  probably,  only  as  the  stroma  or  conidia  of  some  fungus 
of  higher  organization,  possibly  the  Spha?riacei."  This  statement  was 
made  in  discussing  8.  densum,  but  on  the  following  page  (121),  after 
dealing  with  S.  globuliferum,  he  appends  the  following  paragraph: 
"The  remarks  made  under  the  previous  species  are  applicable  to  this, 
which  is  not  entitled  to  rank  as  a  parasite,  but  rather  as  an  accidental 
development  upon  one  out  of  many  forms  of  decaying  animal  matter.'' 

Other  insects  attacked  by  Sporotrichinm  globuliferum, — Spegazzini* 
described  the  species  from  Argentina  as  occurring  on  the  dead  bodies 
of  beetles,  notably  Monocrepidius  and  Naupactus  (vylanthographus. 
Besides Parandra  brunnea,  Professor  Forbes  has  recorded  this  fungus  on 
Laclinosterna,  while  I  have  infected,  artificially,  Epicauta  pennsylvanica 
and  witnessed  an  instance  of  accidental  infection  of  Megilla  maeulata. 
In  both  cases  these  beetles  were  almost  entirely  covered  by  the  fungus 


*  Spegazzini,  Fungi  Argentini,  ii,  p.  42. 


THE  CHINCH  BUG. 


after  having  to  all  appearances  died  from  its  effects.  With  respect  to 
this  matter  one  point  is  clear,  either  the  determination  of  this  fungus 
is  incorrect  or  else  Dr.  Cook  has  made  a  very  serious  misstatement 
which  ought  to  be  corrected.  It  is  but  just  to  state,  however,  that 
Professor  Forbes,  in  his  eighth  report  (p.  23),  calls  attention  to  the  fact 
that  it  is  closely  allied  to  Botrytus,  and  would  be  placed  by  some  botan- 
ists under  that  genus  now.* 

First  artificial  cultivations  of  Sporotrichium  globuliferum — In  April, 
1891,  Dr.  Roland  Thaxter  succeeded  in  cultivating  8.  globuliferum  arti- 
ficially on  agar-agar,  and  a  month  later  Professor  Forbes  made  similar 
cultures  on  the  mixture  of  corn  meal  and  beef  broth,  this  last  being  an 
exceedingly  valuable  discovery,  as  it  revolutionized  our  method  of  dis- 
tributing the  fungus  by  securing  chinch  bugs  to  be  kept  for  a  time 
with  those  diseased,  and  then  sent  out  to  be  scattered  over  the  fields — 
a  cumbersome  method  which  was  never  satisfactory.  My  own  work  in 
Ohio  was  based  on  material  obtained  from  Professor  Forbes,  and  the 
first  year  we  distributed  infected  chinch  bugs,  but  after  that  we  used 
the  artificial  base  of  beef  broth  and  corn  meal,  finding  the  latter  far 
more  satisfactory  to  handle,  and,  so  far  as  I  could  determine,  equally 
effective. 

RESULTS  OF  FIELD  APPLICATIONS  IN  OHIO. 

In  regard  to  my  own  experience,  it  is  unnecessary  to  go  into  details, 
except  to  state  that,  under  the  most  favorable  laboratory  conditions,  I 
was  able  to  kill  apparently  perfectly  healthy  chinch  bugs  within  three 
days  after  bringing  them  in  contact  with  the  Sporotrichium.  In  the 
fields,  during  the  season  of  1895,  though  upward  of  750  packages  of  dis- 
eased bugs  were  sent  out  to  farmers,  and  I  received  some  astonishing 
reports  of  the  results  therefrom,  yet  my  own  observations  led  me  to 
believe  that  in  many  cases  these  were  rather  more  imaginary  than  real. 
Over  the  areas  where  local  showers  occurred  during  the  season  of 
development  of  the  first  brood  of  young  the  effect  was  much  more 
satisfactory.  But  in  many  cases  the  request  for  help  came  late,  and 
soon  after  the  fungus  was  applied  the  bugs  scattered  out  over  the  fields, 
disappearing  to  the  eyes  of  the  ordinary  farmer,  who,  of  course,  attrib- 
uted all  to  the  effect  of  the  Sporotrichium.  In  1890,  however,  meteoro- 
logical conditions  changed,  and  at  last  I  had  the  good  fortune  to  secure 
the  very  opportunity  for  which  I  had  been  waiting  for  years.  All 
through  April  and  up  to  the  10th  of  May  in  southern  Ohio  there  was 
little  rain,  and  even  during  the  remainder  of  the  latter  month  the  light 
rains  hardly  sufficed  to  break  the  drought,  so  that  there  was  a  perfect 

*  Forbes  lias  recorded,  in  his  19th  and  20th  reports,  the  occurrence  of  Sporotrichium 
(jlobuliferum  on  a  number  of  additional  species  of  Coleoptera,  and  also  upon  lepidop- 
terous  larva?,  as  well  as  the  youug  of  other  insects,  and  it  is  probable  that  under 
favorable  conditions  it  will  be  found  to  attack  almost  any  species  more  or  less  readily, 
though  the  present  autumn  we  have  failed  utterly  to  infect  Murganiia  histrionica 
even  when  it  was  placed  among  dying  chinch  bugs  in  our  breeding  cages. 


RESULTS  OF  FIELD  APPLICATIONS  IN  OHIO. 


49 


breeding  season  for  the  chinch  bug  during  the  forepart  of  the  breeding 
period.  The  result  was  that  over  some  sections  (see  fig.  7)  there  were 
myriads  of  young  bugs.  Then  the  rains  came  on,  and  there  were  pre- 
sented the  two  essential  requisites  for  success  with  the  fungus,  viz, 
chinch  bugs  and  wet  weather. 

Soon  the  demands  for  supplies  of  Sporotrichium  began  to  pour  in,  and 
1,200  packages  were  distributed  within  a  few  weeks,  instructions  being 
given  to  place  the  contents  of  the  boxes  where  the  chinch  bugs  were 
massed  in  greatest  abundance,  giving  preference  to  the  lower  and 
damper  localities  in  the  fields. 

After  the  distribution  had  been  finished  I  visited  the  sections  where 
the  outbreak  of  chinch  bugs  had  been  the  most  severe  and  where  the 
larger  portion  of  the  Sporotrichium  had  been  distributed.  There  was 
certainly  no  mistaking  the  effect  of  the  fungus.  Going  to  the  place  in 
a  field  (generally  a  wheat  field)  where  the  fungus  had  been  introduced, 
the  track  of  the  chinch  bugs  as  they  moved  in  any  direction  was  in 
many  cases  almost  literally  paved  with  the  dead  bugs  more  or  less 
enveloped  in  their  winding  sheets  of  white.  Along  ravines,  dead-fur- 
rows, or  other  depressions,  the  ground  would  be  nearly  white,  the  dead 
diminishing  in  numbers  as  the  higher  grounds  were  reached,  though 
these  were  by  no  means  free  from  corpses.  In  one  instance  the  bugs  had 
left  a  field  of  wheat  at  harvest,  the  Sporotrichium  having  been  applied 
there  before  the  movement  began,  and  entered  an  adjoining  cornfield. 
The  way  was  marked  with  white,  not  only  the  surface  of  the  ground,  but 
on  stirring  up  the  mellow  soil  of  the  edge  of  the  cornfield  it  was  found 
to  be  literally  full  of  dead  chinch  bugs  to  the  depth  of  2  or  3  inches, 
the  white  fungus-covered  bodies  strongly  contrasting  with  the  black 
color  of  the  rich  loam.  Not  only  this,  but  under  the  sheaths  of  the 
leaves  and  on  the  leaves  themselves  hundreds  of  dead  were  to  be  found 
on  the  outer  rows  of  corn,  on  the  grass  and  weeds,  and,  indeed,  almost 
everywhere.  Millions  of  chinch  bugs  were  certainly  destroyed  in  tbis 
one  field. 

In  other  fields,  where  the  number  of  bugs  had  been  less,  the  dead 
were  less  numerous,  and  then  they  were  more  apt  to  be  scattered  over 
the  leaves  of  corn,  as  in  such  cases  a  diseased  bug  seems  to  be  animated 
with  a  desire  to  crawl  upward  on  any  object  which  presents  itself,  just 
as  a  larva  of  the  clover-leaf  weevil,  Phytonomus  pimctatus7  when 
attacked  by  Entomophthora  sphwrosperma  (Fres.)  will  climb  to  the  tip 
of  a  vertical  blade  of  grass  and  coil  itself  around  it,  and,  holding  it  in 
the  grasp  of  death,  remain  in  that  position  so  strongly  attached  that 
the  winds  and  rains  fail  to  dislodge  it  until  it  has  become  disintegrated. 
In  other  localities,  where  no  Sporotrichium  had  been  distributed,  the 
ravages  had  certainly  been  greater,  and  I  failed  to  find  any  indication 
of  the  presence  of  the  fungus.  So  far  as  my  observation  extended, 
unless  there  were  a  sufficient  number  of  chinch  bugs  massed  to  become 
injurious,  the  fungus  had  but  little  effect  upon  them.  In  other  words, 
5908— No.  15  1 


50 


THE  CHINCH  BUG. 


bhe  massing  appeared  to  be  an  essential  requisite.  Whether  this  was 
sufficient  of  itself,  or  whether  the  effect  of  massing  was  to  reduce  the 
vitality  of  the  individual  bug,  and  thus  render  it  more  susceptible  to 
the  spores  of  the  fungus,  it  is  impossible  for  me  to  decide;  but  I  have 
long  suspected  that  the  latter  was  the  true  solution  of  the  problem. 
AW'  know  that  most  domestic  animals  or  fowls  thrive  best  and  are 
the  most  vigorous  when  kept  in  small  flocks,  while  among  humans  the 
maximum  of  health  and  minimum  of  disease  is  obtained  where 
the  individuals  are  scattered  over  a  moderate  area  per  capita  and  the 
atmosphere  is  dry  and  pure;  low,  damp,  and  ill- ventilated  quarters, 
when  overcrowded,  being  especially  fatal,  particularly  to  the  young.  The 
individual  in  perfect  health  and  vigor  may  be  said  to  be  above  and  out 
of  reach  of  disease,  and  before  the  two  can  be  brought  together  there 
must  be  some  interacting  element  that  will  bring  the  individual  down 
to  a  point  where  it  can  be  reached  by  the  disease;  that  is,  the  disease 
can  rise  only  to  a  certain  plane  and  the  victim  must  be  first  attacked 
by  some  element  not  necessarily  fatal  in  itself,  but  sufficiently  depres- 
sing to  bring  the  individual  down  to  where  it  can  be  grasped  by  the 
disease. 

Meteorological  influences  favoring  development  of  fungous  enemies  of 
chinch  bug. — When  human  beings  are  overcrowded  and  some  disease 
like  yellow  fever  is  introduced  among  them,  every  one  knows  the  effect 
of  a  low,  damp  locality  under  a  high  temperature  and  with  both  air 
and  water  more  or  less  stagnant.  Even  the  once  healthy  and  vigorous 
are  more  or  less  reduced  and  enervated  by  their  environment,  and  thus 
brought  within  the  influence  of  the  deadly  disease.  Again,  if  an  indi- 
vidual is  stricken  and  forsakes  his  miasmatic  surroundings  for  those 
more  salubrious,  the  disease  may  still  overcome  him,  but  seldom  spreads 
to  others,  except  such  as  come  in  actual  contact  with  either  himself  or 
his  belongings,  while  if  not  too  much  reduced  before  changing  his 
habitation  the  chances  are  much  more  favorable  for  his  recovery. 

It  seems  to  me  that  in  this  matter  of  meteorological  conditions  and 
their  relation  to  the  effect  of  entomogenous  fungi  on  the  chinch  bug 
we  are  really  dealing  with  the  same  problem  in  a  different  field.  The 
young  chinch  bug,  which  has  not  yet  come  into  possession  of  its  full 
measure  of  strength,  and  the  spent  females,  which  have  lost  theirs,  fall 
easiest  as  the  prey  to  these  fungi,  while  the  fully  developed  bugs, 
endowed  with  health  and  vigor,  appear  to  be  to  some  extent  immune 
to  the  attacks  of  these  enemies,  and  if  not  massed  in  large  bodies  they 
seem  still  more  likely  to  escape  destruction.  In  the  timothy  meadows  of 
northeastern  Ohio  I  have  found  an  occasional  dead  adult  in  late  autumn, 
but  the  fungus  had  certainly  not  claimed  many  victims,  though  both 
the  long  and  the  short  winged  forms  were  present  in  considerable  abun- 
dance, clustered  about  the  roots  of  grass.  With  Forbes  I  believe  that 
after  becoming  fully  matured  the  chinch  bug  is,  largely  at  least,  beyond 
the  reach  of  Sporotrichium.    What  is  the  element  that  serves  to  ener- 


A  BACTERIAL  ENEMY. 


51 


vate  and  reduce  the  older  larvre  and  pupre,  as  well  as  many  recently 
developed  adults  among  them?  Is  there  nothing  that,  not  of  itself 
fatal,  so  acts  upon  the  system  of  the  bugs  that  they  are  brought  into 
a  condition  of  susceptibility — a  sort  of  "  go-between,"  so  to  speak,  but 
which  demands  atmospheric  moisture  before  it  will  rise  to  an  aggressive 
state  ? 

A  BACTERIAL  ENEMY  OP  THE  CHINCH  BUG. 

Forbes  finds  that  the  bacterium,  Bacillus  insectorum  Burrill,  is  normal 
to  the  chinch  bug  and  occurs  always  in  the  intestinal  coeca,  and  I  have 
often  wondered  if  this  were  not  the  very  reducing  element.  In  a 
paper  contributed  to  the  "American  Practitioner,"  September,  1891,  he 
describes  the  effect  of  this  bacteria  on  the  coeca  as  completely  destroy- 
ing the  secreting  epithelium,  the  cells  of  which  break  down  and  disap- 
pear, leaving  the  delicate  tubes  filled  with  a  vast  mass  of  microbes  with 
some  small  intermixture  of  droplets  of  fat  and  a  little  nondescript 
debris,  the  result  of  cellular  decomposition.  Now  it  certainly  seems  to 
me  that  we  may  here  have  the  very  enervating  element  necessary  and 
which,  in  order  to  become  sufficiently  aggressive  to  perform  its  func- 
tions perfectly,  requires  the  very  conditions  afforded  by  frequent  show- 
ers, without  which  it  is  comparatively  helpless.  We  know  very  well 
that  human  beings  are  far  more  susceptible  to  disease  when  weakened 
by  fatigue,  dissipation,  or  other  forms  of  exhaustion,  and  under  such 
conditions  succumb  to  disease  when  they  would  otherwise  enjoy  immu- 
nity therefrom.  I  will  not,  however,  follow  this  farther,  but  submit  it 
as  a  problem  well  worthy  of  careful  consideration  and  study.  In  my 
own  experiments  with  Sporotrichium  globuliferum  I  have  found  that 
under  the  most  favorable  conditions  the  fungus  will  attack  even  the 
youngest  larva?,  while  Forbes  states  that  it  will  also  attack  the  eggs, 
but  in  the  fields  I  believe  it  is  generally  most  prevalent  among  the 
more  advanced  larvae,  pupoe,  and  newly  developed  adults,  though  much 
depends  upon  meteorological  conditions  and  the  abundance  of  chinch 
bugs,  as  well  as  the  time  during  the  breeding  season  when  the  fungus 
is  doing  its  work.  That  is  to  say,  there  is  a  time  at  the  beginning  of 
the  breeding  season  when  there  are  only  adults  and  young  larva^  later 
there  will  be  larva}  of  various  ages,  and,  toward  the  last,  few  if  any 
of  these,  but  all  will  be  either  pupae  or  adults.  I  have  for  some  reason 
found  it  more  difficult  to  get  the  Sporotrichium  to  work  satisfactorily 
when  the  chinch  bugs  were  beginning  to  breed  than  later  on,  the  last 
of  June  and  the  early  part  of  July.  These  facts  are  mentioned  here 
to  show  that  judging  by  their  effects  these  fungi  hold  a  secondary 
place. 

THE  PRACTICAL  UTILITY  OF    FUNGOUS  AND    BACTERIAL    ENEMIES  IN  FIGHTING  THE 

CHINCH  BUG. 

Regarding  the  practicability  of  utilizing  these  entomogenous  fungi, 
in  agriculture,  I  see  no  reason  to  revise  my  statement  made  ten  years 


52 


THE  CHINCH  BUG. 


ago.  viz,  that  this  can  be  done  only  in  cases  of  excessive  abundance 
and  during  wet  weather,  the  basis  for  infection  being  provided  by  some 
central  propagating  station  from  which  farmers  can  receive  promptly 
an  abundant  supply.  I  believe  that  for  myself  I  could  manage  to  get 
considerable  benefit  from  their  use  in  destroying  chinch  bugs  provided 
I  was  located  within  the  area  of  the  frequent  occurrence.  This  could 
be  done  only  by  watching  the  seasons  carefully,  and  in  case  there  should 
occur  two  years  in  succession  wherein  the  breeding  periods  were  covered 
by  drought,  then  every  preventive  measure  known  should  be  adopted, 
notably  the  burning  of  leaves,  dead  grass,  and  other  rubbish  during 
winter  or  early  spring  followed  up  by  sowing  small  plats  of  early  millet, 
Hungarian  grass,  or,  better  yet  perhaps,  spring  wheat,  in  low  damp 
places  in  the  fields,  with  a  view  of  attracting  the  females  or  in  fact 
massing  the  bugs,  and  then  freely  applying  the  fungi  in  their  midst. 
Whether  the  ordinary  farmer,  with  his  present  crude  ideas  of  entomology, 
can  do  this  successfully  or  not  is  very  uncertain.  It  is  almost  impos- 
sible to  determine  even  a  few  weeks  in  advance  whether  a  season  is  to 
be  favorable  or  unfavorable  to  the  development  of  the  chinch  bug, 
which  would  of  itself  cause  occasional  false  alarm,  and  the  precautionary 
measures  rendered  entirely  unnecessary  by  a  few  timely  and  drenching 
rains  just  at  the  critical  time.  Before  we  can  expect  to  be  eminently 
successful  in  this  matter,  the  farmer  will  have  to  be  more  thoroughly 
educated,  while  both  the  entomologist  and  meteorologist  have  each 
much  to  learn  in  order  to  properly  enlighten  him. 

THE  QUAIL. 

The  chinch  bug  has  few  important  enemies  among  the  birds  of  the 
northern  United  States.  To  what  extent  the  coast  birds  feed  upon 
them  I  am  unable  to  say,  but  inland  the  common  quail,  Colinus  vir- 
ginianus,  is  the  only  species  that  can  be  said  to  devour  any  consider- 
able number.  As  this  is  one  of  our  most  highly  prized  game  birds,  it  is 
slaughtered  annually  in  tremendous  numbers.  Dr.  L.  O.  Howard*  some 
years  ago  published  a  table  showing  the  season  during  which  quails 
were  protected  by  law  in  the  States  where  chinch  bugs  are  known  to 
commit  their  most  serious  depredations.  At  that  time  (1888)  some  of 
the  Northern  States  had  no  laws  whatever  for  protection  of  quails, 
while  some  protected  them  only  during  the  breeding  season.  In  the 
majority  of  States  the  open  season  extended  from  October  or  Novem- 
ber until  January  or  February,  in  some  instances  until  April.  In 
Dakota  quails  were  protected  absolutely  until  1890,  since  which  time  I 
am  unable  to  state  what  the  laws  are  in  regard  to  the  matter.  Colorado 
protects  them  all  the  time.t 

x   *  Bull.  17,  IT.  S.  Dep.  Agr.,  Div.  Ent.,  pp.  24-25. 

tThe  last  general  assembly  of  Ohio,  1897-98,  restricted  the  open  season  for  quail 
to  within  the  dates  November  10  to  December  15,  and  prohibited  at  all  times  the 
catching  or  killing  of  these  birds  for  the  purpose  of  conveying  the  same  beyond  the 


BIRD  AND  OTHER  ENEMIES. 


53 


The  breeding  season  from  latitude  38°  northward  to  Canada  begins 
in  May,  and  during  some  years  continues  into  September,  a  young  bird 
just  from  the  nest  having  been  taken  in  Wayne  County,  Ohio,  Septem- 
ber 5,  1887.#  There  are  probably  two,  and  southward  three,  broods 
each  season,  and  while  rather  prolific,  they  are  kept  well  reduced  in 
numbers,  at  times  to  the  verge  of  extermination  over  considerable  sec- 
tions of  country.  They  are  hunted  incessantly  and  slaughtered  with- 
out consideration,  except  for  gain.  Also  considerable  numbers  are 
killed  by  flying  against  electric  wires,  while  entire  coveys  sometimes 
are  smothered  or  frozen  under  the  snow.  As  a  result  their  helpfulness 
against  chinch  bugs  is  greatly  diminished. 

OTHER  BIRD  ENEMIES  OF  THE  CHINCH  BUG. 

Among  the  other  bird  enemies  of  the  chinch  bug  are  the  prairie 
chicken,  red -winged  blackbird,  catbird,  brown  thrush,  meadow  lark, 
and  house  wren,  but  there  is  little  doubt  that  the  few  chinch  bugs 
eaten  by  all  of  these  birds  is  insufficient  to  reduce  the  numbers  of  the 
pest  to  any  extent,  and  for  all  practical  purposes  they  might  have 
been  omitted  from  a  list  of  natural  enemies. 

THE  FROG. 

Dr.  Cyrus  Thomas  quotes  Professor  Boss  and  others  as  stating  that 
the  common  frog  is  an  enemy  of  the  chinch  bug.    While  this  is  prob- 
ably true,  it  is  nevertheless  well  known  that  com- 
paratively few  frogs  frequent  grain  fields  as  a  rule, 
and  thus  the  benefit  derived  from  their  attacks  is 
of  too  little  importance  to  merit  further  notice. 

INVERTEBRATE  ENEMIES  OF  THE  CHINCH  BUG. 

Of  the  invertebrate  enemies  the  same  may  be 
said  as  of  the  frog.   The  writer  has  occasionally 
found  a  chinch  bug  containing  a  species  of  Mer- 
mis,  "hair  snake."   Also  occasionally  ants  may 
be  seen  dragging  these  bugs  away,  while  lady-  1 
beetles  have  sometimes  been  found  to  devour  ^'J^S^^Ba^ 
them,  as  recorded  by  Walsh  and  Forbes.  Per- 
haps the  worst  insect  enemies  of  the  chinch  bug  are  to  be  found  among 
its  comparatively  near  relatives,  the  insidious  flower  bug,  Triphleps 
insidiosus  Say  (Anthocoris  pseudo-chinche  of  Fitch's  Second  Report 
(fig.  11),  and  Milyas  ductus  Fab.,  (fig.  12)  the  latter  being  reported  by 
Dr.  Thomas  as  the  most  efficient  of  the  insect  enemies  of  this  pest,  while 
Dr.  Eiley  found  that  the  former  also  attacked  it.    Professor  Forbes 

limits  of  the  State  or  for  sale  within  the  State  for  market  purposes.  The  fish  and 
game  commission  can,  however,  issue  permits  to  colleges  and  educational  institu- 
tions to  collect  both  birds  and  eggs  for  strictly  scientific  purposes. 

*  A  Preliminary  List  of  the  Birds  of  Wayne  County,  Ohio,  by  Harry  C.  Oberholser. 
Bull.  Ohio  Agl.  Exp.  Sta.,  Tech.  Ser.,  Vol.  I,  No.  4,  p.  270. 


54 


THE  CHINCH  RUG. 


ascertained  by  examinations  of  the  contents  of  the  stomach  of  a  ground 
beetle,  Agonoderus  pallipes  Fab.,  that  one-fifth  of  the  total  food  of  this 
species  was  composed  of  chinch  bugs.  Drs.  Shimer  and  Walsh  both 
claim  that  lace-wing  flies  (Chrysopa)  destroy  chinch  bugs,  and  they 
are  doubtless  correct.  I  have  also  very  often  found  chinch  bugs  entan- 
gled in  spider  webs,  dead,  though  whether  killed  for  food  or  by  acci- 
dent I  have  not  been  able  to  determine.  It  will  be  seen,  however,  that 
the  combined  influences  of  all  of  the  natural  enemies  of  the  chinch 
bug,  parasitic  fungi  excepted,  is  far  too  weak  to  offer  any  material  pro- 
tection to  the  agriculturist  against  this  pernicious  enemy  of  his  crops, 
with  nothing  to  promise  an  improved  condition  of  affairs  in  this  direc- 
tion in  the  future.  There  may  sometime  ap- 
pear hymenopterous  parasites  of  the  eggs, 
but  we  have  as  yet  no  proof  of  the  existence 
of  such  in  this  country,  and  only  suspect  the 
possibility  of  such  a  phenomenon  because 
other  allied  species  have  similar  enemies, 
which  destroy  their  eggs.  In  short,  the  im- 
munity of  the  chinch  bug  from  attacks  of 
a  S  b  other  organisms  is  so  striking  that  it  has  at- 
fig. \2.-Miiyas  ductus  Fab.  (from   tracted  the  attention  of  all  entomologists  who 

have  made  a  study  of  the  species,  and  all 
accept  this  as  indicating  that  it  is  an  exotic,  not  originally  belonging 
to  our  insect  fauna. 

REMEDIAL  AND  PREVENTIVE  MEASURES. 

The  list  will  include  all  that  have  been  found  to  possess  the  merit  of 
reasonable  efficiency  and  practicability.  These  measures  may  not  all 
prove  applicable  in  all  localities  or  under  every  variety  of  circum- 
stances, the  farmer  often  having  to  fit  his  protective  measure  to  meet 
weather  conditions,  location  of  field  and  its  surroundings,  as  well  as 
the  thousand  and  one  other  variations  of  a  similar  nature. 

DESTRUCTION  OF  CHINCH  BUGS  WHILE  IN  HIBERNATION. 

The  first  effort  that  may  be  made  with  a  vie w^ of  warding  off  an 
attack  of  chinch  bug  is  to  destroy  them  in  their  winter  quarters.  This 
can  be  accomplished  by  burning  all  dried  grass,  leaves,  or  other  rub- 
bish during  winter  or  early  spring.  Forbes  (First  Report,  p.  37)  and 
Marlatt  (Insect  Life,  VII,  p.  232)  have  cast  some  doubt  upon  the  state- 
ments to  the  effect  that  the  chinch  bug  hibernates  to  any  great  extent 
among  dried  grass,  leaves,  and  rubbish,  but  the  evidence  is  so  over- 
whelmingly in  favor  of  the  assertions  of  nearly  every  entomologist 
who  has  studied  the  insect  in  its  hibernation  to  the  effect  that  it  does 
select  such  places  in  which  to  pass  the  winter  that  there  is  hardly  any 
use  of  raising  the  question  at  all.  A  good  illustration  of  the  fact  that 
large  numbers  of  chinch  bugs  may  be  in  hiding  in  such  places  and 
escape  detectiou  is  shown  by  the  fact  that  a  quantity  of  dried  leaves 


REMEDIAL  AND  PREVENTIVE  MEASURES. 


55 


from  about  a  vineyard  located  on  a  narrow  neck  of  land  about  a  quarter 
of  a  mile  from  the  Bay  of  Sandusky,  on  the  one  side  and  about  1£  miles 
from  the  shores  of  Lake  Erie  on  the  opposite  side,  were  collected  late 
in  April  and  brought  to  our  insectary  and  placed  in  a  breeding  cage. 
At  the  time  of  collecting  the  leaves  only  an  occasional  chinch  bug 
was  to  be  observed,  but  under  the  warm  atmosphere  of  the  insectary 
they  began  to  stir  themselves,  and  soon  demonstrated  that  there  had 
been  a  large  number  ensconced  unseen  among  the  dried  and  curled 
dead  grape  leaves.  So  it  is  with  the  matted  grass  along  roadsides  and 
fences,  especially  the  Virginia  worm  rail-fence. 

While  it  is  not  possible  to  find  them  by  searching,  if  pieces  of  boards 
are  laid  down  on  the  grass  in  early  spring  chinch  bugs  will  collect  on  the 
under  side  and  may  be  found  there,  or  they  may  be  discovered  by  the 
method  of  collecting  known  to  entomologists  as  sifting.  By  burning 
all  such  grass  thousands  of  bugs  will  be  destroyed  in  their  winter 
quarters ;  but  sometimes  the  matted  blue  grass  remains  green  in 
winter,  or  the  weather  is  not  sufficiently  dry  to  enable  the  farmer  to 
burn  over  such  places.  In  such  cases  a  flock  of  sheep  if  given  the 
freedom  of  the  fields  during  winter  and  spring  will  eat  off  all  living- 
vegetation  and  trample  the  ground  with  their  small  feet,  so  that  not 
only  is  all  covering  for  the  bugs  removed  but  they  are  trampled  to 
death  besides.  The  ease  with  which  the  narrow  strip  of  grass  land 
along  a  post  and  wire  fence  can  be  kept  free  of  matted  grass  and  leaves 
as  compared  with  that  along  a  hedge  or  rail  fence  indicates  that  there 
may  be  an  entomological  factor  connected  with  the  modern  fence  that 
has  been  overlooked,  giving  it,  in  this  respect,  an  advantage  over 
the  more  ancient  form.  Shocks  of  fodder  corn  left  in  the  fields  over 
winter  certainly  afford  protection  for  many  chinch  bugs,  as  also  will 
coarse  stable  manure  spread  on  the  fields  before  the  chinch  bugs  have 
selected  their  place  of  hibernation  in  the  fall.  In  short  the  first 
protective  measure  to  be  carried  out  is  a  general  cleaning  up  in  winter 
or  early  spring  either  by  burning  or  pasturing  or  both. 

SOWING  DECOY  PLOTS  OF  ATTRACTIVE  GRAINS  OR  GRASSES  IN  EARLY  SPRING. 

Judging  from  the  manner  in  which  the  wintered-over  adults  are 
attracted  to  hills  of  young  corn,  wheat  fields,  or  plats  of  panic  grass 
and  foxtail,  it  has  always  seemed  to  me  practical  to  take  advantage  of 
this  habit  and  sow  small  patches  of  millet,  Hungarian  grass,  spring 
wheat,  or  even  corn,  early  in  the  spring  and  thus  bait  the  adults  as 
they  come  forth  from  their  places  of  hibernation.  Their  instincts  will 
prompt  them  to  seek  out  the  places  likely  to  afford  the  most  desirable 
food  supply  for  their  progeny,  and  if  an  artificial  supply  can  be  offered 
them  that  will  be  more  attractive  than  that  furnished  by  nature,  the 
bugs  will  certainly  not  overlook  the  fact,  but  will  take  advantage  of  it 
to  collect  together  and  deposit  their  eggs  there,  whereupon  eggs, 
young,  and  adults  can,  a  little  later,  be  summarily  dealt  with  by  plow- 


56 


THE  CHINCH  BUG. 


ing  both  bugs  and  food  under  and  harrowing  and  rolling  the  ground 
to  keep  the  former  from  crawling  to  the  surface  and  escaping.  I  have 
thoroughly  tested  this  method  in  a  case  where  the  bugs,  young  and 
old,  had  taken  possession  of  a  plat  of  neglected  ground  overrun  with 
panic  grass  (Panietm  crus-galli),  which  was  mown  and  promptly 
removed  and  the  ground  plowed,  harrowed,  and  rolled  before  the  bugs 
could  escape,  thus  burying  them  beneath  several  inches  of  soil  out  of 
which  they  were  unable  to  make  their  way,  and  as  a  consequence  they 
were  almost  totally  annihilated,  hardly  1  per  cent  making  their  escape 
to  an  adjoining  cornfield. 

DIFFICULTY  OF  REACHING  CHINCH  BUGS  IN  MEADOWS. 

There  is,  however,  some  doubt  in  regard  to  the  practicability  of 
applying  these  measures  in  meadows.  Meadow  lands  can  be  burned 
over  with  perfect  safety  to  either  the  grass  or  clover,  if  done  while  the 
ground  is  frozen,  but  there  is  danger  of  injury  if  burned  over  in 
spring,  and  it  is  somewhat  doubtful  if  the  hibernating  chinch  bugs 
wTould  be  killed  unless  the  surface  of  the  ground  was  heated  to  a 
degree  that  the  grass  and  clover  plants  would  hardly  be  able  to 
withstand. 

Infested  areas  of  meadow  land  could  be  plowed,  it  is  true;  but  the 
work  would  have  to  be  done  very  carefully,  else  the  grass  and  stubble 
would  be  left  to  protrude  above  ground  along  each  furrow  and  consti- 
tute so  many  ladders  by  which  the  chinch  bugs  could  easily  crawl  out 
and  make  their  escape.  Where  the  ground  will  admit  of  subsoiling,  or 
a  "jointer"  plow  can  be  used,  this  latter  difficulty  can  easily  be  over- 
come. Usually,  however,  the  chinch  bug  works  too  irregularly  in  a 
field  to  permit  of  plowing  under  infested  areas  without  disfiguring  it 
too  much  for  practical  purposes,  especially  in  the  case  of  meadows, 
unless  it  be  where  the  bugs  have  migrated  en  masse  from  an  adjoining 
field,  when  a  narrow  strip  along  the  border  can  often  be  sacrificed  to 
good  advantage.  I  have  witnessed  many  instances  where  the  heroic 
use  of  the  plow  in  turning  under  a  few  outer  rows  of  corn  would  have 
saved  as  many  acres  from  destruction.  In  the  majority  of  cases  it  is 
the  fault  of  the  farmer  himself  that  these  measures  are  not  effective,  as 
he  will  seldom  take  the  trouble  to  burn  the  dead  leaves,  grass,  and 
trash  about  his  premises  at  the  proper  time,  and  when  there  occurs  an 
invasion  of  chinch  bugs,  instead  of  resorting  to  heroic  and  energetic 
measures  to  conquer  them  on  a  small  area  he  usually  hesitates  and 
delays  in  order  to  determine  whether  or  not  the  attack  is  to  be  a  seri- 
ous one,  and  by  the  time  he  has  decided  which  it  is  to  be,  the  matter 
has  gone  too  far,  and  the  chinch  bugs  have  taken  possession  of  his  field. 
This  is  especially  true  in  the  West,  where  the  bugs  breed  exclusively 
in  the  fields  of  wheat  and  remain  unobserved  until  harvest,  when  they 
suddenly  and  without  warning  precipitate  themselves  upon  the  grow- 
ing corn  in  adjacent  fields.  In  fighting  the  chinch  bug  promptness  of 
action  is  about  as  necessary  as  it  is  in  fighting  fire. 


REMEDIAL  AND  PREVENTIVE  MEASURES. 


57 


WATCHFULNESS  NECESSARY  DURING  PROTRACTED  PERIODS  OP  DROUGHT. 

It  lias  always  appeared  to  me  as  though  a  little  watchfulness  on  the 
part  of  farmers  during  periods  of  drought  might  enable  them  to  deter- 
mine whether  or  not  chinch  bugs  were  present  in  any  considerable  num- 
bers in  their  fields  in  time  to  interpose  a  strip  of  millet  between  the 
wheat  and  corn,  to  be  utilized  later  as  previously  indicated.  Instances 
have  come  under  my  observation  where,  the  wheat  fields  being  over- 
grown with  panic  grass  and  meadow  foxtail,  the  bugs  transferred  their 
attention  to  these  as  soon  as  the  wheat  was  harvested,  and  a  prompt 
plowing  of  the  ground  would  have  placed  the  depredators  beyond  the 
possibility  of  doing  any  serious  injury.  If  the  weather  at  the  time  is 
hot  and  dry  a  mower  may  be  run  over  the  stubble  fields  or  along  the 
borders  of  them,  cutting  off  grass,  weeds,  and  stubble,  as  the  case  may 
be,  leaving  it  to  dry  in  the  hot  sun,  when,  in  a  few  hours,  it  will  burn 
sufficiently  to  roast  all  bugs  among  it,  and,  while  not  destroying  every 
individual,  this  will  reduce  their  numbers  to  such  an  extent  that  they 
will  be  unable  to  work  any  serious  injury. 

In  case  the  weather  at  the  time  should,  on  the  contrary,  be  wet  and 
rainy,  so  that  it  is  impossible  to  mow  and  burn,  the  prompt  distribution 
of  the  fungus  Sporotrichium  will  prove  of  immense  value;  for  in  this 
case  the  more  the  bugs  are  massed  over  a  limited  area,  the  more  fatal 
will  be  the  effects  of  the  fungus,  and  especially  will  this  prove  true  if 
the  land  is  low  and  inclined  to  be  damp.  This  statement  will  also  hold 
good  with  reference  to  meadow  lands  during  the  breeding  season, 
though  later  the  adults  do  not  appear  to  succumb  to  the  effects  of  the 
fungus  nearly  as  readily,  and  I  have  found  it  present  in  spring  among 
masses  of  hibernating  individuals,  with  little  indications  of  its  conta- 
gious nature,  only  an  occasional  individual  being  attacked. 

UTILITY  OF  KEROSENE  IN  FIGHTING  CHINCH  BUGS. 

In  fighting  the  chinch  bug  there  is  at  present  no  more  useful  sub- 
stance than  kerosene,  either  in  the  form  of  an  emulsion  or  undiluted. 
From  its  penetrating  nature,  prompt  action,  and  fatal  effects  on  the 
chinch  bug,  even  when  applied  as  an  emulsion,  it  becomes  an  inex- 
pensive insecticide,  while  it  has  the  further  advantage  of  being  an 
article  of  universal  use  in  every  farmhouse,  and  is  therefore  always  at 
hand  for  immediate  use.  The  emulsion  has  the  further  advantage  of 
being  capable  of  sufficient  reduction  in  strength  to  prove  fatal  to  insect 
life  and  yet  not  injure  the  vegetation  upon  which  such  may  be  depre- 
dating. Diluted  and  ready  for  use,  the  emulsion  is  prepared  as  fol- 
lows: Dissolve  one-half  pound  of  hard  soap  in  1  gallon  of  water, 
preferably  rain  water,  heated  to  the  boiling  point  over  a  brisk  fire,  and 
pour  this  suds  while  still  hot  into  2  gallons  of  kerosene.  Churn  or 
otherwise  agitate  this  mixture  for  a  few  minutes  until  it  becomes  of  a 
cream-like  consistency,  which,  on  cooling,  will  form  a  jelly-like  mass 
which  adheres  to  the  surface  of  glass  without  oiliness.   For  each  gallon 


58 


THE  CHINCH  BUG. 


of  this  emulsion  use  15  gallons  of  water,  mixing  thoroughly,  and  if 
applied  to  growing  corn  it  will  be  best  to  use  it  either  during  the 
morning  or  evening,  say  before  8  a.  m.  or  after  5  p.  m.,  as  it  will  be  less 
likely  to  affect  the  plants  than  if  applied  in  the  heat  of  the  day. 

Where  an  invasion  of  the  chinch  bug  is  in  progress  from  a  field  of 
wheat  to  an  adjoining  field  of  corn,  as  an  illustration,  the  marginal 
rows  of  corn  can  frequently  be  saved,  even  after  the  bugs  have  massed 
upon  the  plants,  by  spraying  or  sprinkling  them  freely  with  kerosene 
emulsion,  using  a  sufficient  quantity  so  that  the  emulsion  will  run 
down  and  reach  such  bugs  as  are  about  the  bases  of  the  plants.  This 
treatment  will  kill  the  bugs  clustered  upon  the  corn,  and  in  case  of 
those  on  the  way  to  the  field,  while  it  will  not  keep  them  out,  it  will 
cause  a  halt  in  the  invasion,  and  thus  give  the  farmer  an  opportunity 
to  put  other  measures  in  operation,  and  one  of  these  measures  will 
include  the  use  of  kerosene  in  another  manner.  If  a  deep  furrow  is 
plowed  along  the  edge  of  the  field,  running  the  land-side  of  the  plow 
toward  the  field  to  be  protected,  the  furrow  will  form  a  temporary 
barrier  to  the  incoming  hordes. 

UTILITY  OF  DEEPLY  PLOWED  FURROWS  SUPPLEMENTED  BY  THE  USE  OF  KEROSENE 

EMULSION. 

In  dry  weather  the  sides  of  this  furrow  can  be  made  so  steep  and  the 
soil  so  finely  pulverized  that  when  the  chinch  bugs  attempt  to  crawl 
up  out  of  the  furrow  they  will  continually  roll  back  to  the  bottom, 
where  they  can  be  sprinkled  with  either  kerosene  alone  or  with  the 
much  less  expensive  emulsion,  and  killed.  In  case  of  showery  weather, 
which  prevents  the  sides  of  the  furrow  from  remaining  loose  and  dry, 
the  bottom  can  be  cleared  out  with  a  shovel,  making  it  more  smooth 
and  the  sides  more  perpendicular,  thus  rendering  it  so  much  easier  to 
follow  along  the  bottom  than  to  attempt  to  climb  the  sides.  If  holes 
are  dug  across  the  bottom  at  distances  of,  say,  30  or  40  feet,  the  bugs 
will  fall  into  them  and  can  be  still  more  easily  disposed  of  by  the  use 
of  kerosene.  That  both  of  these  measures  are  thoroughly  practical  I 
have  ample  personal  experience  in  evidence,  and  know  that  under  most 
conditions  that  are  likely  to  obtain,  prompt  and  efficient  application  is 
all  that  is  necessary.  During  a  few  days  this  work  will  demand  the 
closest  watching  and  application,  but  fields  of  grain  can  be  protected 
thoroughly  and  effectually  if  these  measures  are  faithfully  carried  out, 
and  the  expense  of  time  and  money  will  be  found  to  be  less  than  in 
almost  any  other  plan  that  has  been  up  to  this  time  discovered.  I  have 
never  seen  a  field  attacked  by  a  migrating  army  of  chinch  bugs  but 
that  it  might  have  been  saved  from  very  serious  injury  by  the  prompt 
use  of  either  of  these  measures,  though  I  can  imagine  conditions  where 
the  farmer  might  find  it  advantageous  to  use  some  other  method  of 
protection. 


REMEDIAL  AND  PREVENTIVE  MEASURES. 


59 


THE  RIDGE  AND  COAL  TAR  METHOD. 

Differing  quite  materially  from  the  preceding  are  the  various  com- 
binations of  coal  tar  and  ridges  of  earth,  smoothed  and  packed  along 
the  apex,  or,  instead  of  the  ridge  of  earth,  6-inch  boards,  such  as 
are  ordinarily  used  for  fencing,  placed  on  edge  and  the  upper  edge 
coated  with  tar.  Forbes  has  reported  excellent  results  from  the  appli- 
cation of  a  line  of  coal  tar  put  directly  upon  the  bare  ground  where  the 
surface  has  been  rendered  compact  by  a  recent  fall  of  rain.  Even  in 
this  series  of  protective  measures  kerosene  can  be  used  to  great 
advantage.  In  the  experiment  recorded  by  Professor  Forbes  the  coal 
tar  was  put  upon  the  ground  between  a  wheat  field  and  a  corn  field 
from  an  ordinary  garden  sprinkling  pot  from  which  the  sprinkler  had 
been  removed  and  the  orifice  of  the  spout  reduced  in  size  with  a  plug 
of  wood  until  the  tar  came  out  in  a  stream  about  the  size  of  the  little 
finger  and  made  a  line  on  the  surface  of  the  ground  about  three-fourths 
of  an  inch  in  width.  Post  holes  were  sunk  along  the  line  from  10  to 
20  feet  apart  on  the  side  next  to  the  wheat  field,  thus  practically  com- 
pleting the  barrier,  and  the  chinch  bugs  being  unable  to  cross  the  line 
of  tar  accumulated  in  the  post  holes  in  vast  numbers,  where  they  were 
killed,  and  those  bugs  that  had  already  entered  the  cornfield  before 
the  barrier  was  constructed  were  prevented  from  spreading  further  by 
tar  lines  between  the  rows  of  corn,  the  infested  corn  itself  being  cleared 
of  bugs  by  the  application  of  kerosene  emulsion.  The  same  writer 
states*  that  several  farmers  in  Vermilion  County,  111.,  prepared  for  the 
coaltar  line  by  hitching  a  team  to  a  heavy  plank  and  running  this, 
weighted  down  with  three  or  four  men,  over  the  ground  once  or  twice 
until  a  smooth,  hard  surface  had  thus  been  made  to  receive  the  tar. 
If  the  barrier  was  to  be  made  in  sod,  a  furrow  was  plowed  and  the 
bottom  of  this  made  smooth  by  dragging  the  plank  along  the  bottom. 
In  both  cases  post  holes  were  sunk  along  the  tar  lines,  and  in  these 
were  placed  cans  or  ws  into  which  the  bugs  fell  in  myriads  and  were 
destroyed. 

On  one  farm  of  250  acres  a  coal-tar  line  90  rods  in  length  was  renewed 
once  each  day  and  killed  about  8  gallons  of  chinch  bugs.  In  the  case 
of  another  farmer  there  were  300  rods  of  tar  lines  with  post  holes,  cans, 
etc.,  which  resulted  in  destroying  about  10  bushels  of  chinch  bugs. 
A  6-gallon  jarful  was  destroyed  in  less  than  half  a  day  at  one  point 
on  the  line.  In  this  last  instance  the  lines  of  tar  were  renewed  three 
times  a  day,  but  even  then  less  than  a  barrel  of  tar  wras  used.  Still 
another  farmer,  with  120  rods  of  tar  line,  used  about  a  third  of  a  barrel 
of  tar  and  did  not  lose  a  hill  of  corn;  he  caught  chinch  bugs  by  the 
bushel.  In  some  of  the  cases  cited  the  tar  line  was  run  in  a  zigzag 
course,  the  post  holes  being  situated  at  the  angles,  and  in  others  leader 
tar  lines  were  run  obliquely  to  the  main  tar  line,  one  end  terminating 

*  Twentieth  Report  of  State  Entomologist  of  Illinois,  p.  39,  1898. 


60 


THE  CHINCH  BUG. 


at  the  trapnole,  but  both  of  these  plans  were  afterwards  regarded  as 
unnecessary,  a  single  straight  line  being  entirely  sufficient  and  less 
expensive.  The  numerous  cases  where  these  methods  were  put  into 
execution  with  entire  success  and  at  small  expense  is  the  best  possi- 
ble proof  of  their  practical  utility.  If  a  farmer  is  situated  near  town, 
where  refuse  tin  cans  are  dumped  in  any  locality  where  they  can  be 
got  out  of  the  way,  he  can  select  the  larger  of  these,  set  them  in  the 
post  holes  and  partly  fill  them  witli  kerosene  and  water.  The  water 
being  heavier  than  the  kerosene  will  sink  to  the  bottom,  leaving  a 
stratum  of  kerosene  on  the  surface.  The  chinch  bugs  falling  into  this 
will  be  forced  down  by  the  weight  of  those  coming  after,  and  thus  all 
will  be  passed  through  the  kerosene  into  the  water  below.  This  will 
obviate  the  necessity  of  frequently  emptying  the  cans  or  treating  their 
contents.  It  may  also  be  stated  that  where  the  post  holes  are  quite 
deep  and  enlarged  at  the  bottom  the  bugs  falling  into  them  will  perish 
without  further  attention. 

OTHER  BARRIER  METHODS. 

Professor  Snow,  working  in  Kansas,  followed  a  somewhat  different 
method  and  one  that,  under  certain  conditions,  might  be  found  supe- 
rior to  that  used  by  Professor  Forbes,  or  the  furrow  and  kerosene 
method  applied  by  myself  in  Ohio.  This  modification  consists  in 
throwing  up  a  double  furrow,  known  among  farmers  as  "back  furrow- 
ing," and  thus  forming  a  ridge,  the  top  of  which  is  smoothed  and 
packed  with  a  drag  having  a  concave  bottom  of  the  form  of  the  ridge 
to  be  made.  If  the  bottom  of  this  drag  is  covered  with  zinc  it  will  be 
found  to  keep  bright  and  polished  and  by  this  means  make  a  more 
smooth  ridge.  The  substances  used  were  coal  tar  as  it  came  from  the 
gas  works  and  crude  petroleum  as  taken  from  the  oil  wells.  The 
former  is  the  more  easily  obtained,  except  in  certain  localities,  and 
will  probably  be  found  the  more  practicable,  as  it  stands  on  the  surface 
better  and  is  not  so  readily  washed  away  by  rains.  Both  of  these  sub- 
stances are,  however,  offensive  to  the  bugs,  and  they  will  seldom 
attempt  to  cross  them  or  even  come  close  enough  to  touch  them,  but 
on  approaching  will  turn  and  run  along  the  ridge  in  the  evident  hope 
of  finding  a  gap  through  which  they  can  pass.  Post  holes  were  dug 
on  the  outside  of  the  line,  but  close  up  to  it,  so  that  the  bugs  in  pass- 
ing along  beside  the  tar  line  would  crowd  each  other  into  them.  Pro- 
fessor Snow  suggests  that  it  will  be  better  to  construct  this  barrier 
several  weeks  prior  to  its  being  needed,  as  then  the  tar  line  has  but  to 
be  run  along  the  ridge  and  the  post  holes  dug,  when  the  whole  system 
is  complete  and  the  chinch  bugs  can  be  thus  shut  out  from  the  first.* 

With  these  barriers  of  either  ridge  or  furrow  and  the  use  of  coal  tar 
X)r  crude  petroleum,  supplemented  by  kerosene  emulsion,  a  very  large 

*  Fifth  annual  Report  of  the  Director  of  the  Experimental  Station  of  the  Uni- 
versity of  Kansas,  pp.  45-47. 


REMEDIAL  AND  PREVENTIVE  MEASURES. 


61 


per  cent  of  the  injury  from  chinch  bugs  may  be  prevented,  and,  in  fact, 
with  a  reasonable  degree  of  watchfulness  and  prompt  action,  all  injury 
from  migrating  hordes  may  be  prevented.  The  use  of  tarred  boards 
set  on  edge  or  slightly  reclining  might,  under  some  circumstances,  take 
the  place  of  the  ridge  or  furrow,  but  these  cases  will  be  exceptional, 
and  the  use  of  kerosene  emulsion  will  probably  be  found  equally  prac- 
tical here,  as  also  will  the  post  holes  for  collecting  the  chinch  bugs.  I 
merely  cite  this  method  in  order  to  call  attention  to  its  possible  use 
where  the  others  are  found  impractical.  The  plowing  of  furrows  has 
been  in  vogue  since  the  first  writings  of  Le  Baron  and  the  second  report 
of  Dr.  Fitch,  and  may  be  utilized  in  other  ways  than  those  previously 
mentioned.  A  heavy  log  dragged  back  and  forth  in  this  furrow  will 
pulverize  the  soil  in  dry  weather,  and  Forbes  has  recorded  the  fact  that 
where  this  has  a  temperature  of  110°  to  116°  F.  it  is  fatal  to  the  young 
bugs  that  fall  into  the  furrow,  even  if  they  are  not  killed  by  the  log. 
As  120°  is  not  uncommon  in  an  exposed  furrow  on  a  hot  summer  day, 
it  will  be  observed  that  there  may  be  cases  where  this  method  will  be 
found  very  serviceable,  and  especially  is  this  likely  to  prove  true  in  a 
sandy  soil  with  a  southern  exposure.  In  sections  of  the  country  where 
irrigation  is  practiced  these  furrows  may  be  flooded  aud  in  this  way 
rendered  still  more  effective  without  the  expenditure  of  either  time  or 
money  to  keep  them  in  constant  repair.  Dr.  Riley  long  ago  laid  con- 
siderable stress  on  this  measure,  believing  it  of  much  value,  especially 
in  the  arid  regions  of  the  far  West.  The  same  writer  advised  the  flood- 
ing of  infested  fields,  wherever  it  could  be  done,  for  a  day  or  so  occa- 
sionally during  the  month  of  May.  It  is  hardly  likely,  however,  that 
this  will  often  be  found  feasible,  though  such  occasions  might  arise. 

NECESSITY  FOR  PREVENTING  CHINCH  BUGS  FROM  BECOMING  ESTABLISHED  IN  FIELDS 

OF  WHEAT  AND  GRASS. 

In  the  foregoing  it  will  be  observed  that  prevention  of  migration  has 
been  the  chief  end  in  view  either  by  destroying  the  chinch  bugs  in  their 
hibernating  quarters,  and  thus  preventing  the  spring  migration  to  the 
breeding  places,  or  by  various  traps  and  obstructions  to  prevent  them 
from  migrating  from  such  places  to  others  not  already  infested.  The 
great  problem  remaining  to  be  solved  is  to  prevent  their  breeding  in 
wheat  fields  at  all.  As  I  have  shown,  it  is  absolutely  impossible,  with 
our  present  inability  to  forecast  the  weather  months  in  advance,  to  be 
able  to  foretell  whether  or  not  an  outbreak  of  chinch  bug  is  likely  to  take 
place.  There  may  be  an  abundance  of  bugs  in  the  fall — enough  to  cause 
an  outbreak  over  a  wide  section  of  country — and  these  may  winter  over 
in  sufficient  numbers  to  cause  some  injury  in  spring,  yet  a  few  timely, 
drenching  rains  will  outbalance  all  of  these  factors,  and  our  wisest 
prognostications  fail  of  proving  true.  It  is  this  very  factor  of  uncer- 
tainty that  renders  the  carrying  out,  over  any  large  area  of  country, 
any  protective  measures  where,  as  in  this  case,  the  benefit  to  be  derived 


G2 


THE  CHINCH  BUG. 


will  only  be  realized  ueaiiy  a  year  afterwards,  if  at  all.  The  average 
farmer,  when  smarting  under  a  heavy  loss,  will  often  take  such  long- 
range  precautions  as  to  sow  belts  of  Hax,  hemp,  clover,  or  buckwheat 
around  his  wheat  held  once,  but  if  the  chinch  bugs  do  not  appear,  and 
he  sees  the  useless  investment  of  time,  labor,  and  seed,  he  will  likely 
conclude  the  next  year  to  take  the  risk  and  do  nothing.  For  the  pres- 
ent, then,  we  have  no  method  whereby  we  can  prevent  the  chinch  bugs 
from  taking  up  their  abode  in  wheat  fields  or  timothy  meadows  and 
raising  their  enormous  families  there,  except  to  destroy  the  adults  in 
their  winter  quarters. 

I  once  tried  to  destroy  the  young  in  a  wheat  field  by  spraying  with 
kerosene  emulsion  the  small  areas  of  whitening  grain  that  indicated 
where  the  pests  were  massed  in  greatest  abundance.  The  result  was 
unsatisfactory,  and  it  is  very  doubtful  if  it  is  possible  to  apply  this 
measure  with  any  degree  of  success,  and  we  are  forced  to  the  conclusion 
that,  for  the  present  at  least,  we  shall  be  obliged  to  rely  upon  the 
measures  previously  given.  It  therefore  becomes  of  the  utmost  impor- 
tance to  clean  up  the  roadsides,  and  along  fences  and  patches  of  wood- 
land, as  well  as  any  other  places  likely  to  afford  protection  for  the 
hibernating  chinch  bugs.  I  fully  understand  the  obstacles  in  the  way 
of  carrying  out  this  plan  generally  over  any  large  area  of  country,  and 
especially  in  sections  where  the  rail  fence  predominates.  But  as  the 
country  gets  older  it  will  be  found  that  it  is  not  chinch  bugs  alone  that 
seek  these  places  in  which  to  pass  the  winter,  but  myriads  of  the  other 
insect  foes  of  the  farmer  as  well,  and  that  careful  attention  to  the  con- 
dition of  roadsides,  lanes,  hedgerows,  and  waste  places  about  the 
farms,  during  the  season  when  insects  seek  out  these  places  wherein  to 
pass  the  winter,  will  pay  well  for  the  time  expended  in  that  direction. 
It  may  come  about  that  some  phase  of  the  street-cleaning  reform  may 
invade  the  country,  and  it  is  certain  that  if  such  were  to  occur  it 
would,  in  time,  save  the  country  enough  to  go  far  toward  reducing  the 
expense  of  securing  good  roads.  In  fact,  the  term  u  good  roads"  ought 
to  include  the  proper  care  of  the  roadsides,  as  well  as  the  grading  and 
macadamizing  of  the  roadbed  itself. 

There  are  at  present  so-called  weed  laws  in  many  States,  and  though 
more  or  less  of  a  dead  letter  in  most  cases,  yet  these  laws  are  steps  in 
the  proper  direction.  The  time  when  insect  pests  will  be  looked  upon 
in  the  eye  of  the  law  as  so  many  xmblic  nuisances,  and  the  harboring 
of  them  a  corresponding  crime,  may  be  a  long  way  off*,  but  as  it  grad- 
ually draws  nearer  to  us  we  shall  come  to  learn  that,  after  all,  it  is  the 
rational  view  to  take  and  will  go  far  toward  solving  not  only  the 
chinch  bug  problem  but  many  others  of  a  similar  nature.  So  far  as  the 
chinch  bug  is  concerned,  when  we  burn  over  the  waste  lands  and 
accumulated  rubbish  about  our  farms  in  autumn  or  winter,  we  are 
simply  applying  the  same  check  that  the  dusky  savage  did  when  he 
lighted  the  prairie  fires,  though  unwittingly  and  for  an  entirely  differ- 


SUMMARY  OF  REMEDIAL  AND  PREVENTIVE  MEASURES.  63 


eiit  purpose.  In  the  timothy  meadows  of  the  northeastern  portion  of 
the  country,  where,  for  lack  of  wings  fitted  for  locomotion,  the  chinch 
bug  does  not  so  largely  migrate  to  the  waste  lands  in  autumn,  the 
problem  is  somewhat  different,  and  it  will  require  some  careful  experi- 
ments to  determine  the  exact  effects  of  burning  over  the  meadow  lauds 
in  winter,  both  on  the  hibernating  chinch  bugs  and  on  the  grass  roots. 
There  can  be  little  doubt,  however,  that  a  rapid  rotation  of  crops,  so  as 
not  to  allow  the  short-winged  form  to  become  thoroughly  established 
in  a  meadow,  and  burning  over  the  waste  places  and  such  rubbish  and 
debris  as  will  serve  to  offer  hibernating  places  for  the  long-winged  form, 
will  go  far  toward  settling  the  chinch  bug  problem  in  grass  lands. 

As  previously  stated,  the  chief  difficulty  in  putting  preventive  meas- 
ures in  force  is  in  the  difficulty  of  foretelling  an  invasion.  In  north- 
eastern Ohio  in  1897  hundreds  of  acres  of  timothy  meadow  were 
destroyed  after  the  hay  crop  had  been  removed,  but  so  late  that  the 
farmers  did  not  suspect  the  true  condition  of  their  meadows  until  the 
spring  of  1898,  when  the  young  grass  failed  to  put  forth  and  an  exam- 
ination revealed  the  fact  that  the  roots  had  been  killed,  the  abundance 
of  chinch  bugs  pointing  unerringly  to  the  cause  of  the  trouble,  though 
in  many  cases  a  heavy  crop  of  hay  had  been  removed  the  previous  year 
where  now  the  ground  was  entirely  bare.  While  in  the  case  just  cited 
a  previous  knowledge  of  the  presence  of  chinch  bugs  in  these  meadows 
might  not  have  enabled  the  owners  to  have  saved  them  in  the  fall  of 
1897,  yet  the  fall  plowing  of  the  land,  possibly  early  enough  to  have 
sown  the  ground  to  fall  wheat,  would  have  buried  the  majority  of  the 
bugs  so  deeply  in  the  soil  as  to  have  killed  vast  numbers  of  them  and 
thus  prevented  their  migrating  to  other  lands  in  the  spring  of  1898.* 
A  rotation  of  crop  that  would  have  included  grass  for  not  to  exceed 
two  successive  years,  followed  by  wheat,  wrould  have  amounted  to 
precisely  the  same  remedial  measure  as  the  one  suggested. 

SUMMARY  OF  REMEDIAL,  AND  PREVENTIVE  MEASURES. 

In  summing  up  the  matter  of  remedial  and  preventive  measures 
for  the  control  of  the  chinch  bug,  it  may  be  stated  that  the  insects  may 
be  destroyed  in  their  places  of  hibernation  by  the  use  of  fire.  They 
can,  under  favorable  meteorological  conditions,  be  destroyed  in  the 

*  A  case  in  northeastern  Ohio  has  come  to  my  notice  where  an  infested  timothy 
meadow  was  plowed  late  in  the  fall  of  1897.  Late  in  April  of  1898  this  ground  was 
cultivated,  rolled,  and  harrowed  several  times,  and  most  carefully  and  completely 
prepared  for  corn,  which  was  planted,  but  with  the  result  that  a  portion  of  the  field 
was  attacked  and  destroyed  by  chinch  bugs,  largely  of  the  brachypterous  form.  An 
examination  about  June  10  revealed  the  bugs  in  considerable  numbers  about  the 
still  remaining  plants,  but  scattered  over  the  field  were  more  or  less  numerous 
clumps  of  timothy,  in  some  cases  apparently  having  been  killed  by  the  chinch  bugs, 
while  in  others  these  were  literally  swarming  about  the  dying  but  still  green  clumps 
of  grass,  thus  showing  that  the  former  had  either  not  been  buried  by  the  plowing 
and  cultivation  of  the  ground,  or  else  the  grass  had  not  been  thoroughly  covered, 
and  thus  ladders  had  been  left  whereby  they  were  enabled  to  climb  to  the  surface. 


64 


THE  CHINCH  BUG. 


fields,  if  present  in  sufficient  abundance  during  the  breeding  season, 
by  the  use  of  the  fungus  Sporotriclmm  globuliferum,  if  promptly  and 
carefully  applied.  They  can  be  destroyed  while  in  the  act  of  migrating 
from  one  lield  to  another  by  tarred  barriers,  or  deep  furrows  supple- 
mented by  post  holes,  and  by  being  buried  under  the  surface  of  the 
ground  with  the  plow  and  harrow;  or  the  latter  method  can  be  applied 
after  the  bugs  have  been  massed  upon  plots  of  some  kind  of  vegetation 
for  which  the  bugs  are  known  to  have  a  special  fondness,  which  decoys 
should  be  so  arranged  as  to  either  attract  the  females  and  induce  them 
to  oviposit  therein,  or  they  should  be  arranged  with  the  idea  of  inter- 
cepting an  invasion  from  wheatfields  into  cornfields,  and,  by  turning 
these  decoys  under  with  a  plow  and  immediately  smoothing  and  pack- 
ing the  surface  by  harrow  and  roller,  thus  destroying  them.  While  in 
the  cornfields  they  can  be  destroyed  on  the  plants  by  applications  of 
kerosene  emulsion.  Without  vigilance  and  prompt  action,  however, 
only  indifferent  results  are  to  be  expected  from  any  of  these  measures. 

INSECTS  THAT  ARE  MISTAKEN  FOll  CHINCH  BUGS. 

Messrs.  Osborn  and  Mally*  have  given  a  list  of  twelve  species  of 
Hemiptera  which  have  been  mistaken  with  more  or  less  frequency  for 
the  chinch  bug,  the  list  being  as  follows: 

Nysius  angustatus  Uhl.,  the  false  chinch  bug  (fig.  13),  is  probably  the 
most  frequently  mistaken  for  the  true  chinch  bug,  as  it  often  breeds  in 

considerable  numbers  under  purslane,  ama- 
ranth, etc.,  and  more  than  any  other  insect 
resembles  the  chinch  bug.  It  is,  however, 
of  a  light-gray  color,  which  will  always  dis- 
tinguish it  from  its  more  destructive  fellow. 

Ischnodemus  f aliens  Say,  or  the  long  chinch 
bug,  as  it  is  sometimes  called,  is  much  larger 
and  longer  than  the  true  chinch  bug. 
Ischnorhynchus   didymus   Zett.  is  more 

Fig.  13.— Nysius  angustatus:  b,  pu-  -.. 

pa;  c,  mature  bug  (from  Kiiey).  robust,  of  a  light-tawny  color,  with  promi- 
nent, glassy  wings. 
Peliopelta  abbreviata  Uhl.  is,  next  to  the  false  chinch  bug,  probably 
the  most  often  mistaken  for  the  true  insect,  and  especially  is  this  true 
in  localities  where  the  brachypterous  form  of  Blissus  leucopterus 
abounds.  In  timothy  meadows  I  have  more  than  once  been  misled. 
Its  broader  head  and  body,  however,  quickly  enabled  me  to  distin- 
guish it. 

Geocoris  fuliginosus  Say,  G.  borealis  Dallas,  G.  bullatus  Say,  and  G. 
Umbatus  Stal.,  according  to  Osborn  and  Mally,  have  all  been  confused 
with  the  chinch  bug  in  Iowa.  These  are  all  broader  and  flatter  than 
the  true  chinch  bug,  the  head  being  nearly  as  wide  as  the  thorax. 

*  Bulletm.  No.  32,  Iowa  Agricultural  College  Experiment  Station,  pp.  363-385. 


INSECTS  MISTAKEN  FOR  CHINCH  BUGS. 


65 


Ligyrocoris  sylvestris  Linn,  is  larger  than  the  true  chinch  bug,  and 
its  wings  are  quite  dark  instead  of  white. 

Trapezonotas  nebulosus  Fall,  is  a  trifle  larger  and  its  body  is  not  so 
black  as  in  the  chinch  bug. 

Cymodema  tabida  Spin.,  is  longer  than  the  true  chinch  bug,  of  alight 
brown  color,  and  the  ends  of  the  wings  are  glassy. 

TriphJeps  insidiosus  Say,  or  the  insidious  flower  bug 
(fig.  11),  as  it  is  more  commonly  called,  is  another  bo- 
gus chinch  bug,  though  an  enemy  of  the  true  pest,  as 
previously  stated. 

Piesma  cinerea  Say,  the  ash-gray  leaf  bug  (fig.  14)  is 
often  mistaken  for  the  true  chinch  bug,  though  its 
form  differs  greatly  from  that  of  the  latter.  It  is  often 
quite  abundant,  but  not  in  grain  fields  or  meadows. 

Corimelcena  pulicaria  Germ.,  the 
flea  like  negro  bug  (fig.  15),  has 
been  confused  with  the  chinch  bug ; 
though  it  does  not  in  the  least  re- 
semble the  latter,  either  in  form  or  color,  and  its 
confusion  is  probably  to  be  accounted  for  by  the 
fact  of  its  being  occasionally  found  in  wheat  fields 
in  considerable  numbers. 

Brachyrhynchus  granulatus  Say  (fig.  16),  has  been 
mistaken  for  the  chinch  bug  in  Ohio,  and  in  a  way  that  was  somewhat 
amusing.    Farmers  in  southern  Ohio,  during  the  winter  of  1896-97,  were 


Fig.  14. — Piesma  cine 
rea  (from  Riley). 


Fig.  15.— Corimelcena  pu- 
licaria (from  Riley). 


burning  over 
stroying  the 
came  several 


the  woodlands  with  a  view  of  de- 
hibernating  insects,  when  there- 
discouraging  reports  to  the  effect 
that  such  a  course  would  be  in- 
effective, as  the  bugs  were  winter- 
ing in  the  tops  of  trees,  especially 
where  the  tops  were 
dead,  under  the  bark 
and  often  from  50  to 
75  feet  from  the 
ground.   This  was  a 
piece  of  astounding 
information,  to  me 
at  least,  and  it  was 
only  after  securing 
specimens  that  I  was 
able  to  solve  the 

mystery.   This  insect,  in  all  stages  of  development  except  the  egg, 
hibernates  under  loose  bark.    It  is  broader  and  much  flatter  than  the 
true  chinch  bug,  but  the  wings  are  white  and  the  body  black. 
The  object  in  calling  attention  to  these  bogus  chinch  bugs  is  to  pre- 
5968— No.  15  5 


Fig.  16. — Brachyrhynchus  granulatus:  a,  early  nympl 
c,  late  nympli— all  enlarged  (from  Hart). 


b,  adult; 


66 


THE  CHINCH  BUG. 


vent  their  confusion  with  the  true  Blissns  leucopterus,  as  in  some  cases 
people  finding  them  and  supposing  them  to  be  the  true  pest,  are  likely 
to  become  panic  stricken  and  often  destroy  property  unnecessarily,  so 
notorious  has  the  name  "chinch  bug"  become  in  the  United  States. 

PROBABLE  ORIGIN  AND  DIFFUSION  OF  THE  CHINCH  BUG. 

For  the  farmer  engaged  in  attempts  to  check  the  ravages  of  the 
insect  in  his  fields  the  question  of  origin,  or  how  it  came  to  reach  him, 
will  at  the  time  have  little  interest  for  him.  It  will  suffice  that  it  is 
present  in  overwhelming  numbers,  and  what  he  will  most  desire  will  be 
to  learn  how  to  rid  his  premises  of  its  most  unwelcome  presence  in  the 
most  summary  manner  possible. 

If,  however,  the  farmer  happens  to  be  a  thoughtful  and  observing  man 
he  will  sometimes  wonder  how  it  is  that,  except  in  Virginia  and  the 
Carolinas,  a  person  need  not  be  very  aged  in  order  to  remember  a  time 
when  the  chinch  bug  was  an  unknown  factor  in  his  profession,  with  a 
possible  value  far  too  small  to  merit  consideration.  If  he  happens  to 
reside  in  northeastern  Ohio  or  in  some  portions  of  New  York,  and  has 
spent  some  time  in  Illinois,  Iowa,  Kansas,  or  Minnesota,  he  will  prob- 
ably marvel  at  the  striking  difference  in  appearance  between  many  of 
the  chinch  bugs  of  his  own  locality  and  those  found  in  any  of  the  last- 
mentioned  States,  and  will  probably  be  able  to  satisfy  himself  of  their 
identity  only  by  the  similarity  of  their  vile  odor.  Again,  he  will  prob- 
ably be  equally  at  a  loss  to  understand  why  it  is  that  his  own  timothy 
meadows  are  overrun  by  these  pestiferous  insects  and  destroyed, 
while  in  other  localities,  perhaps  less  than  100  miles  away,  similar 
meadows  are  left  untouched,  the  injury  there  being  confined  to  the 
wheat  and  corn  fields. 

If  wondering  leads  to  questioning,  as  it  often  does  among  the  con- 
stantly increasing  number  of  educated  and  up-to-date  farmers,  it  will 
not  satisfy  him  to  receive  an  evasive  or  obscure  reply  to  his  query  as  to 
why  such  differences  exist,  for  if  he  can  not  get  a  clear  explanation  he 
will  want  ideas,  theories,  or  possibilities.  He  wants  the  best  explana- 
tion possible  to  give  until  some  one  finds  out  a  better  one,  realizing 
that  had  mankind  been  perfectly  satisfied  with  the  knowledge  that  a 
stroke  of  lightning  would  split  a  tree  or  destroy  human  life,  and  had 
stubbornly  refused  to  listen  to  possibilities  or  to  anything  but  facts, 
we  would  not  now  be  able  to  understand  and  utilize  electricity  in  the 
many  ways  that  we  do  at  the  present  time.  Such  men  understand, 
perfectly,  that  the  solution  of  most  problems  in  natural  science  must 
of  necessity  commence  with  theories  which  must  be  patiently  tested 
and  adopted  or  rejected  as  the  results  demand,  while  the  scientific  man 
knows  that  the  solution  of  one  problem  often  opens  up  the  way  for  the 
v  solution  of  another,  the  last  not  infrequently  having  an  entirely  differ- 
ent application  from  the  first. 

The  science  of  applied  entomology  is  growing  rapidly  and  becoming 


PROBABLE  ORIGIN  AND  DIFFUSION. 


67 


both  broader  and  deeper,  aud  it  is  not  enough  to  simply  tell  the  hus- 
bandman what  an  insect  is  and  how  to  kill  it.  He  must  have  some- 
thing along  with  that  information  to  set  his  own  mind  to  thinking,  to 
work  out  problems  or  improve  upon  the  solutions  already  given  him, 
otherwise  it  is  much  like  giving  money  to  a  professional  beggar.  If  we 
can  not  give  facts  based  upon  demonstrations,  then  give  the  best  expla- 
nation possible,  even  though  it  be  a  theory  which  is  only  expected  to 
stand  until  some  one  does  better.  It  is  for  the  thoughtful,  progressive 
farmer,  as  well  as  the  student  of  geographical  distribution,  that  this 
possible  solution  of  the  problem  of  the  chinch  bug  has  been  prepared, 
and  while  the  full  practical  value  of  the  ideas  advanced  has  yet  to  be 
demonstrated,  this  of  itself  can  not  be  urged  as  sufficient  grounds  for 
not  sending  it  forth  for  study  and  consideration. 

Thanks  to  the  careful  observations  of  Professor  Sajo,  on  the  Euro- 
pean species  of  chinch  bug,  Blissus  dorice,  it  is  now  for  the  first  time 
possible  to  compare  the  habits  of  this  species  with  our  own. 

INDICATIONS  OF  A  PROBABLE  DISTANT  ORIGIN  AND  LATER  DIFFUSION. 

In  the  United  States  our  chinch  bug,  Blissus  leucopterus,  has  a  num- 
ber of  peculiar  characteristics,  which,  while  having  an  economic  inter- 
est, also  points  to  a  probable  previous  condition  differing  somewhat 
from  the  present,  and  not  in  all  cases  tending  toward  its  present  nu- 
merical strength.  On  the  other  hand,  we  find  that  it  is  now  following 
some  probably  ancient  habits  which  do  not  appear  to  be  of  any  special 
benefit,  but  rather  the  reverse. 

In  the  first  place,  over  its  area  of  greatest  destruction,  it  appears  to 
prefer  level  tracts  of  country  where  the  damp  conditions  consequent 
upon  frequent  rainfalls  remain  the  longest,  and  in  the  second  place, 
the  period  of  spring  oviposition  is  for  the  most  part  included  within 
that  during  which  the  spring  rains  of  the  United  States  usually  occur — 
that  is  to  say,  throughout  the  great  grain  belt,  east  of  the  Eocky 
Mountains,  April  and  May  are  not  normally  months  of  severe  drought, 
and  it  is  during  these  two  months  that  the  larger  portion  of  the  eggs 
are  deposited.  As  in  the  reverse  of  this,  however,  the  period  of  fall 
oviposition,  August  and  September,  is  far  more  likely  to  be  favored  by 
a  lack  of  precipitation.  These  conditions  do  not  always  obtain,  and  it 
is  because  of  the  fluctuations  that  the  insect  is  able  to  reach  its  maxi- 
mum in  poiut  of  numbers. 

Another  factor  which  plays  quite  an  important  part  in  reducing  the 
number  of  adults  maturing  during  unfavorable  seasons  may  be  found 
in  the  almost  universally  gregarious  habits  of  the  young,  thereby  ren- 
dering the  ravages  of  the  fungous  disease  the  more  universal  and  fatal. 
In  all  of  these  peculiar  characteristics  as  well  as  in  some  anatomical 
features,  it  seems  to  me  we  have  a  series  of  guide  posts,  so  to  speak, 
which  indicate  more  or  less  clearly  the  ancient  home  of  the  species, 
and  at  least  throw  some  light  on  its  origin  and  diffusion. 


68 


THE  CHINCH  BUG. 


UNIQUE  APPEARANCE  AND  GREGARIOUS  HABIT. 

Mr.  E.  A.  Schwarz*  sometime  ago  called  attention  to  "  the  unique 
appearance  of  the  full-grown  chinch  bug,  with  its  white  wings  and 
chalky- white  pubescence,"  which,  he  declared,  "forcibly  indicates  that 
the  insect  is  either  a  psammophilous  or  a  maritime  species,"  and 
expressed  the  opinion  that  its  geographical  distribution  fully  bears 
out  the  theory  that  it  belongs  to  the  latter  class.  The  same  author 
states  that  the  species  has  the  habit  of  clustering  about  the  roots  of 
tufts  of  grass  along  the  Atlantic  coast,  from  Florida  to  Atlantic  City, 
J.,  and  Mr.  W.  H.  Harrington  t  observed  it  to  have  the  same  habit 
along  the  seashore  at  Sydney,  Cape  Breton,  in  1884.  The  late  Dr.  J.  C. 
Neal,  while  at  Stillwater,  Okla.,  wrote  me  that  he  had  observed  the 
species  to  have  the  same  habit  in  that  Territory,  miles  from  any  human 
habitation.  Dr.  Asa  Fitch  f  found  them  swarming  amidst  extensive 
prairies  in  Illinois,  in  1854,  while  more  recently  Mr.  0.  L.  Marlatt  has 
witnessed  the  same  phenomenon  in  Kansas.  §  In  short,  this  gregarious 
habit  seems  to  be  most  tenaciously  adhered  to  wherever  these  insects 
are  found  in  any  numbers.  Wheu  migrating  from  one  field  to  another, 
after  crossing  a  roadway  or  plowed  field  they  will  at  once  flock  together 
on  a  few  plants  along  the  margin  of  the,  to  them,  new  field  instead  of 
scattering  about,  two  or  three  to  a  plant.  It  may  also  be  added  that 
Mr.  Koebele  found  the  species  in  large  numbers  along  the  seashore  not 
far  from  £>an  Francisco,  Gal.,  in  the  first,  second,  and  third  stages  of 
development,  on  a  species  of  grass  growing  along  the  coast. 

It  has  not,  so  far  as  is  known  to  the  writer,  been  observed  in  similar 
places  along  the  shores  of  the  Great  Lakes,  though  I  have  searched  for 
it  there,  but  it  occurs  in  destructive  abundance  in  timothy  meadows 
inland  in  northeastern  Ohio  for  fully  75  miles,  and  most  generally 
clustering  about  the  roots  of  grass,  which,  by  the  way,  is  about  the 
only  vegetation  attacked  as  the  species  is  described  as  doing  along  the 
seacoasts.  I  may  say  also,  that  it  seems  to  hibernate  there  precisely 
as  observed  by  Mr.  Marlatt  in  Kansas  j  Dr.  Neal  in  Oklahoma  ;  Mr. 
Schwarz  in  Virginia  in  the  vicinity  of  Fortress  Monroe,  and  as  the 
earlier  observations  of  Dr.  Fitch  in  Illinois  would  imply.  Thus  we 
find  this  habit  of  clustering  upon  the  plants  attacked  to  be  a  constant 
one,  and  where  the  natural  grass  vegetation  has  not  been  displaced  by 
farm  crops,  thus  leaving  the  ground  more  or  less  bare  during  winter, 
they  continue  to  hibernate  there.  With  these  two  characteristic  habits 
generally  followed  over  the  great  area  inhabited  by  the  species  in 
North  America,  we  may  add  a  third  possible  factor  in  the  problem 
of  origin  and  diffusion  of  the  species  which,  though  an  anatomical 
dimorpniain,  may  be  discussed  as  likely  to  throw  considerable  light 
upon  the  probable  ancient  habitat  of  the  insect. 

*  Insect  Life,  Vol.  VII,  p.  420. 

t  Can.  Ent.  Vol.  XXVI,  p.  218. 

J.  Second  Report,  Insects  of  New  York,  p.  283. 

§  Insect  Life,  Vol.  VII,  pp.  232-234. 


PROBABLE  OEIGIX  AND  DIFFUSION. 


69 


OCCURRENCE  OK  THE  LONG  AND  SHORT  WINGED  FORMS  AND  THEIR  DISTRIBUTION. 

The  occurrence  of  both  the  long  and  short-winged  forms,  intermixed 
along  our  seacoasts  and  in  the  northeastern  section  of  the  country, 
but  not  elsewhere,  shows  very  plainly  that  this  dimorphism  is  not  due 
to  the  temperature  of  any  particular  locality,  but  must  be  regarded  as 
having  been  brought  about  by  disuse  of  the  wings  for  a  considerable 
period  of  time,  thus  indicating  a  seashore  habit  on  the  one  side,  while 
the  total  lack  of  the  short-winged  form  elsewhere  indicated  otherwise. 

In  a  paper  presented  before  the  Entomological  Society  of  Washing- 
ton,* "On  the  insects  found  on  Uniola panicula  in  southeastern  Florida,1' 
by  Mr.  E.  A.  Schwarz,  the  author  stated  that  Blissus  leucopterus  occurred 
in  large  numbers  on  the  upper  part  of  the  plant,  the  imagos  and  larger 
young  among  the  ears  and  the  smaller  individuals  between  the  upper 
blades.  Mr.  Schwarz  attributes  this  habit  to  the  tough  woody  nature 
of  the  storm-beaten  plant  nearer  the  ground,  thereby  driving  the  insects 
to  the  more  tender  though  more  exposed  portion  of  the  plant.  In  con- 
nection with  this  statement  the  writer  tells  us  that  the  insect  occurs 
in  that  southern  latitude  only  in  the  short-winged  form,  and  that  in  the 
examination  of  thousands  of  specimens  from  that  region  he  had  never 
found  a  single  long- winged  specimen.  Under  date  of  May  4,  1896,  Mr. 
W.  H.  Harrington  wrote  ine  of  this  species  as  follows:  "In  September, 
1890, 1  found  it  at  Aulac,  almost  on  the  border  between  Xew  Brunswick 
and  Xova  Scotia.  It  seemed  not  uncommon  and  occurred  under  stones, 
about  the  roots  of  grass,  in  a  pasture  adjoining  the  marsh  where  I 
found  Diabrotica  longicornis,  the  pasture  being  on  the  upland  skirting 
the  marsh.  Both  the  long  and  short-winged  condition  occurred,  as  in 
Cape  Breton.  +  Dr.  A.  S.  Packard  communicated  to  Dr.  J.  A.  Lintner  the 
following  extract  from  his  diary,  "June  17, 1871,  at  Salem,  Mass.,  chinch 
bugs  with  wing  covers  extending  over  the  basal  third  of  the  abdomen, 
seen  in  copula,  end  to  end.t  In  the  serious  outbreak  of  this  insect  in 
the  timothy  meadows  of  northern  New  York,  in  1882  and  1883,  about 
20  per  cent  of  the  bugs  were  of  this  short- winged  form.§ 

Although  Dr.  Asa  Fitch,  as  early  as  1855,  refers  to  this  form  along 
with  nine  others,  he  does  not  give  the  source  from  which  he  obtained 
specimens,  but  just  previous  to  this  he  says  (p.  287)  that  he  had  met 
with  but  three  specimens  from  his  own  State,  and  these  were  found  on 
willow  in  the  spring  of  1847.||  Had  any  of  these  been  of  the  short- 
winged  form  he  would  have  been  very  likely  to  have  mentioned  the 
fact.  Mr.  E.  P.  Yan  Duzee*]  states  that  he  had  known  of  the  occur- 
rence of  the  species  in  western  New  York  as  early  as  1874,  and  had 
also  found  it  at  Ridgeway  and  Muskoka,  Ontario.     Ordinarily  the 

*  Proc.  Ent.  Soc,  Washington,  Vol.  I,  p.  104.    Bead  Xov.  3, 1887. 
t  Canadian  Entomologist,  Vol.  XIV,  p.  218. 

t  Lintners  Second  Eeport,  State  Entomologist  of  New  York,  p.  164. 
$  Second  Eeport,  State  Entomologist  of  Xew  York,  p.  156. 
||  Second  Eeport  on  Noxious  Insects  of  Xew  York,  p.  291. 
H  Canadian  Entomologist,  Vol.  XVII,  pp.  209-10,  1886. 


70 


THE  CHINCH  BUG. 


short- winged  form  predominates,  but  in  hot,  dry  summers  they  mostly 
acquire  fully  developed  wings.  He  had  never  found  the  species  in 
grain  fields  of  any  sort,  but  always  in  grass  lands,  generally  in  timothy 
or  clover,  but  sometimes  in  wild  grasses.  Of  eleven  specimens  collected 
from  under  the  bark  of  an  old  log  by  Mr.  J.  Pettit,  of  Grimsby, 
Ontario,  in  18G6,  and  sent  to  Mr.  B.  D.  Walsh  for  determination,  all 
were  of  the  short- winged  form.*  It  was  these  specimens  that  doubt- 
less led  Dr.  Riley  t  to  call  attention  to  the  fact  that  in  Europe  there  ai  e 
many  genera  of  half-winged  bugs  which  occur  in  two  distinct  or 
"  dimorphous"  forms  with  no  intermediate  grades  between  the  two, 
viz.,  a  short  winged  or  sometimes  a  completely  wingless  type  and  along- 
winged  type.  Frequently  the  two  occur  together  and  copulate  pro- 
miscuously, while  sometimes  the  long-winged  type  occurs  in  particular 
seasons,  especially  in  very  hot  seasons,  while  more  rarely  the  short- 
winged  type  occurs  in  a  different  locality  from  the  long-winged  type, 
and  usually  in  that  case  in  a  more  northern  locality.  In  northeastern 
Ohio  the  species  occurs  during  some  years  in  great  abundance  and  very 
largely  at  least  on  timothy.  Here  the  short-winged  form  is  very  largely 
in  the  majority,  and  in  the  spring  of  1897,  of  1,900  specimens  collected 
indiscriminately,  only  about  400  were  of  the  long-winged  type. 

In  northern  Indiana,  where  the  insect  occurs  but  rarely,  I  have  also 
found  this  short-winged  type,  though  I  have  not  observed  that  it  pre- 
dominates; but  aside  from  these  two  localities,  with  an  acquaintance 
with  this  species  running  over  forty  years,  chiefly  in  Indiana  and 
Illinois,  I  have  never  met  with  the  short- winged  type,  though  I  have 
seen  millions  of  adults,  t  If  this  short-winged  type  occurs  elsewhere  to 
the  westward,  except  along  the  Pacific  coast,  where  both  forms  have 
been  collected  by  Keobele  and  others,  it  has  not  been  found  by  ento- 
mologists, even  to  the  northward  as  far  as  Minnesota,  Winnipeg,  and 
Manitoba,  while  to  the  eastward  of  this  Mr.  Van  Duzee  collected  the 
brachypterous  form  on  Muskoka  River,  Ontario,  near  the  lake  of  that 
name.  §  On  comparing  specimens  from  Xew  York  with  a  large  series 
from  Kausas,  the  former  were  found  to  be  quite  uniformly  more  robust, 
with  longer  hairs  on  the  pronotum.  || 

It  seems  to  me  that  we  here  have  evidence  of  two  distinct  tides  of 
migration,  the  oue  sweeping  north  and  eastward,  while  the  other  has 
mainly  been  to  the  north  and  westward,  meeting  the  former  in  north- 
eastern Ohio  and  northern  Indiana,  and  possibly  somewhere  farther  to 

*  Practical  Entomologist,  Vol.  II,  p.  21. 

t  Second  Report  on  the  Insects  of  Missouri,  p.  22,  1870. 

t  Of  a  large  number  of  adults  collected  late  in  April,  1898,  while  still  in  hibernation 
among  the  dead  leaves  in  vineyards  near  the  shore  of  Lake  Erie,  in  northwestern 
Ohio,  not  a  single  brachypterous  individual  occurred,  while  of  66  specimens  sent 
me  from  Salem,  in  northeastern  Ohio,  50  miles  from  the  lake  shore,  May  31,  1898, 
all  but  6  were  brachypterous,  these  latter  being  taken  from  a  field  of  young  corn, 
8  acres  of  which  had  been  totally  destroyed  by  them. 

§  Can.  Ent.  Vol.  XXI,  p.  3,  1889. 

||  Loc.  cit.  Vol.  XVIII,  p.  209. 


PROBABLE   COURSE  OF  DIFFUSION. 


71 


the  north  in  British  America.  The  two,  besides  differing  in  the  length 
of  the  wings,  are  sufficiently  unlike  in  appearance  to  attract  the 
attention  of  students  of  Hemiptera. 

RELATION  OF  THE  INLAND  AND  SEACOAST  SHORT- WINGED  FORMS. 

I  do  not  wish  to  be  understood  as  claiming  that  the  short-winged 
form  of  chinch  bug  found  in  Ohio  is  precisely  the  same  form  as  that 
found  along  the  seacoasts,  but  it  seems  to  me  that  the  inland  form 
originating  from  this  maritime  short-winged  element,  instead  of  acquir- 
ing wings  of  normal  length  as  it  drifted  away  from  the  coast,  has  really 
moved  in  the  other  direction,  and  the  wings  have  become  still  further 
aborted. 

It  will  be  observed  by  the  illustrations  given  of  both  the  inland  and 
maritime  short-winged  forms  (see  figs.  3  and  4),  that  in  some  of  the 
former  the  wings  have  become  so  aborted  as  to  become  almost  invisi- 
ble, while  in  the  latter,  though  the  wings  are  very  much  shortened, 
they  are  nevertheless  very  clearly  to  be  observed.  It  would  seem,  then, 
that  we  might  reasonably  presume  that  the  species  was  originally 
long-winged,  but,  living  along  the  seashore,  the  winged  individuals 
have  either  flown  each  year  inland  or  else  been  blown  into  the  sea  to 
such  an  extent  that  a  short-winged  form  has  thus  been  evolved  which 
was  unable  to  migrate  and  not  easily  blown  into  the  sea.  In  pushing 
inland  while  the  country  was  still  inhabited  by  the  aborigines  another 
source  of  destruction  would  confront  these  insects  in  the  annual  recur- 
rence of  fires  whereby  vast  areas  of  country  were  burned  over  in 
autumn,  winter,  or  early  spring,  and  these  must  have  destroyed  very 
many  of  the  hibernating  insects,  while  such  individuals  as  migrated  to 
sections  not  so  burned  over  would  escape  destruction. 

PROBABLE  COURSE  OF  DIFFUSION. 

Let  us  suppose  that  the  species  originally  worked  its  way  northward 
from  South  America,  or  even  Panama,  along  the  lowlands  between  the 
more  mountainous  interior  aud  the  Gulf  of  Mexico  until  it  reached 
Texas,  with  its  vast  areas  of  level  country  extending  not  only  across 
the  State  itself,  but  northward  into  British  America,  and,  generally 
speaking,  with  the  exception  of  the  Ozark  Mountains  in  Missouri  and 
Arkansas,  eastward  to  the  Appalachian  system  extending  from  Cape 
Gaspe,  Quebec,  Canada,  to  northern  Alabama.  This  area  is  more  or 
less  covered  with  a  grass  flora  that  affords  ample  food  for  these  insects, 
and  it  would  seem  that  there  was  here  offered  every  incentive  to  migra- 
tion broadly  to  the  northward  and  eastward,  and  at  the  same  time 
there  would  be  the  Gulf  coast  along  which  those  individuals  which 
either  could  not  or  did  not  migrate  inland  could  make  their  way  as  had 
their  progenitors  along  the  coast  in  Mexico.    (See  fig.  17.) 

Now,  it  would  appear  as  though  the  short  winged  individuals,  if  there 
were  any  such,  would  remain  along  the  coast,  while  the  long- winged 


Fig.  17.— Map  showiug  probable  course  of  diffusion  of  chinch  bug  over  North  America  (author's  illustration). 


PROBABLE  COURSE  OF  DIFFUSION.  73 


individuals  would,  at  least  more  or  less  of  them,  migrate  inland,  and 
at  least  some  of  these,  but  far  more  of  those  unable  to  fly,  would 
be  annually  destroyed  by  the  prairie  fires,  thus  eliminating  whatever 
tendency  there  might  be  to  perpetuate  the  brachypterous  forms,  and 
develop  a  fully  wiuged  more  or  less  nomadic  race  which,  as  it  slowly 
advanced  inland,  lost  all  vestige  of  its  brachypterous  ancestry,  if  such 
had  existed.* 

On  the  other  hand,  we  might  expect  the  shore-inhabiting  individuals 
to  continue  in  their  progress  along  the  coast,  the  wiuged  individuals 
continually  migrating  inland,  leaving  a  mixture  of  the  two  forms  to 
push  forward  to  the  east  coast  of  Florida  and  northward  along  the 
Atlantic  to  Cape  Breton.  As  soon  as  this  migration  had  passed  the 
southern  terminus  of  the  Alleghany  Mountains  the  inland  spread 
would,  very  largely  at  least,  be  restricted  to  the  area  lying  between  the 
eastern  slope  of  these  mountains  and  the  coast,  thus  leaving  the  whole 
area  to  the  west  to  be  occupied  by  the  northward  tide  of  migration 
instead  of  that  from  the  east.  East  of  the  Mississippi  River  and  south 
of  the  Ohio  River  the  country  is  more  heavily  timbered  and  the  prai- 
ries are  lacking,  so  that  forest  fires  would  here  take  the  place  of  prairie 
fires;  but  in  the  Southern  States  the  woods  are  composed  more  largely 
of  pine,  and  Dr.  Lugger,  in  Minnesota,  finds  that  the  chinch  bug  does 
not  invade  the  region  on  which  only  pine  and  other  Conifera?  grow,  but 
that  the  more  southern  counties  of  his  State,  which  are  well  wooded 
with  deciduous  trees,  are  invaded.  He  also  calls  attention  to  the  fact 
that  before  the  country  was  settled  by  the  whites  these  timbered  lands 
were  burned  over  frequently,  probably  annually,  but  now  the  wooded 
areas  are  confined  to  small  tracts  interspersed  among  the  farms,  and 
as  these  are  not  annually  burned  over  they  afford  suitable  shelters  for 
the  chinch  bug  during  winter,  and  the  grain  fields  of  the  farmer  afford 
ample  food  during  the  summer,  while  on  the  prairies  which  are  burned 
over  such  is  not  the  case,  t 

Along  the  eastern  coast  the  chinch  bug  has  never  been  especially 
destructive  to  the  wheat  crop  north  of  North  Carolina,  where,  accord- 
ing 4:o  Dr.  Fitch,  i:  the  earliest  depredations  occurred  in  1783,  while 
Webster  §  states  that  it  threatened  total  destruction  to  the  grain  in 
1785;  but  since  that  time  the  ravages  have  not  been  nearly  as  severe  as 
farther  west  in  the  Mississippi  River  valley.  Strangely,  too,  nowhere 
along  the  Atlantic  coast  do  we  find  the  short-winged  form  far  inland 
until  we  reach  New  York  and  the  New  England  States,  and  what  is 

*Prof.  H.  A.  Morgan,  entomologist  of  the  State  Experiment  Station  of  Louisiana, 
writing  me  under  date  of  May  30,  1898,  states  that  he  has  never  found  the  brachyp- 
terous  form  of  chinch  hug  in  that  State,  and  I  did  not  ohserve  a  single  individual 
of  these  among  the  many  macropterous  specimens  taken  by  myself  in  that  State. 

t First  Annual  Report  of  the  Entomologist  of  the  State  Experiment  otation  of  the 
University  of  Minnesota,  1895,  p.  26. 

t  Second  Report  on  Noxious,  Beneficial,  and  other  Insects  of  New  York,  p.  278. 

§  Webster  on  Pestilence,  Vol.  I,  279. 


74 


THE  CHINCH  BUG. 


equally  perplexing,  there  it  does  not  attack  grain,  but  grass,  whereas 
to  the  southward  it  is  the  grain  fields  that  are  devastated,  lu  other 
words,  throughout  New  England,  New  York,  northeastern  Ohio,  north- 
ern Indiana,  and  the  Dominion  of  Canada  we  have  both  the  long  and 
short  winged  forms  occurring  together,  but  depredating  almost  or  quite 
exclusively  upon  timothy  (Phleum  prateme). 

In  Ohio  the  line  separating  the  habitat  of  the  combined  forms  and 
that  of  the  macropterous  form,  exclusively,  exactly  marks  the  line  of 
separation  between  the  most  serious  depredations  and  almost  total 
immunity  of  attack  on  timothy  meadows  by  chinch  bugs.  This  line  of 
demarcation  at  present  may  be  indicated  approximately  by  a  line 
drawn  from  the  vicinity  of  the  city  of  Cleveland,  on  Lake  Erie,  to  the 
point  where  the  Ohio  Kiver  ceases  to  form  the  boundary  between  Ohio 
and  West  Virginia  and  enters  Pennsylvania.  To  the  west  and  south 
of  this  I  have  never  seen  a  short-winged  adult  chinch  bug,  and  timothy 
meadows  are  seldom  attacked,  and  then  only  where  fields  of  small 
grain  or  corn  were  not  in  easy  reach;  as,  for  illustration,  where  they 
happened  to  breed  in  a  wheat  field  surrounded  by  timothy,  and,  when 
the  grain  was  harvested,  there  was  no  other  recourse  left  them  but  to 
attack  the  grass.  In  the  opposite  direction  from  our  line,  however,  the 
conditions  are  quite  the  reverse.  Here,  while  fields  of  wheat  are  occa- 
sionally badly  injured,  thousands  of  acres  of  timothy  meadow  have 
been  entirely  killed  out  from  the  attack  of  this  insect  during  the  last 
few  years. 

So  far  as  it  is  possible  to  determine,  there  are  a  considerable  number 
of  winged  adults  produced  in  this  area  every  year — perhaps  from  30  to 
50  per  cent  some  seasons — and  these  breed  in  the  grain  fields;  but  at 
wheat  harvest,  instead  of  migrating  to  the  corn,  as  is  done  elsewhere, 
they  go  by  preference  to  the  timothy  meadows.  In  western  New  York, 
where  both  the  long  and  short  winged  forms  occur,  Mr.  Yan  Duzee 
writes  me  that  he  has  never  found  an  individual  of  either  form  in  grain 
fields,  but  that  they  both  literally  swarm  in  timothy  during  some  years. 
Dr.  Lintner  told  me  that  in  the  serious  outbreak  of  this  pest  in  the 
meadows  of  New  York  in  1882  and  1883  about  20  per  cent  were  of  the 
short- winged  form.  Dr.  Perkins  has  recorded  an  attack  of  chinch  bug 
in  a  timothy  meadow  in  northern  Vermont.  Whether  or  not  the  short- 
winged  form  was  the  depredator  in  this  last-named  locality  I  am  unable 
to  say,  but,  generally  speaking,  the  short-winged  form  is  unknown  at 
any  considerable  distance  from  the  coast,  except  in  New  Yrork,  Ohio, 
Ontario,  and  northern  Indiana,  and  but  rarely  does  it  occur  in  either 
form  in  the  two  latter  localities. 

Just  why  this  short-winged  form  should  occur  in  such  abundance  in 
the  two  States  named  is  a  matter  that  I  am  just  at  present  unable 
tally  to  explain;  but  it  does  seem  that  this  difference  in  food  habits  as 
between  the  two  forms  and  the  limited  distribution  of  the  short- winged 
form  inland  might  open  the  way  to  a  solution  of  the  mystery.    I  believe 


HABITS  OF  THE  EUROPEAN  SPECIES. 


75 


that  the  insect  is  primarily  a  tropical  macropterous  species,  and  that  it 
has  followed  the  coast  from  South  America  along  the  Gulf  and  Atlantic 
northward  to  Cape  Breton,  and  along  the  Pacific  coast  to  San  Fran- 
cisco and  possibly  beyond  j  also  that  it  spread  from  northern  Mexico 
and  Texas  northward  as  far  as  Winnipeg,  subsisting  upon  the  native 
grasses,  and  in  the  meantime  spreading  also  to  the  eastward  to  northern 
Indiana  and  Ohio,  and  that  during  this  time,  by  force  of  circumstances, 
it  has  again  become  fully  winged  and  all  trace  of  its  former  apterous 
condition,  if  such  exists,  has  disappeared. 

On  the  other  hand,  from  the  Atlantic  coast  there  has  originated  a 
tide  of  diffusion  the  trend  of  which  has  been  westward,  the  species 
here  partakiug  more  of  the  nature  of  their  seashore  ancestry,  and  are 
more  or  less  of  the  short-winged  form,  which  their  less  nomadic  habit 
has  served  to  further  emphasize.  This  tide  of  diffusion  has  encountered 
what  the  western  tide  did  not,  at  least  until  much  later,  namely,  the 
timothy  meadows  of  the  Caucasian  agriculturist,  and,  adapting  itselt 
to  this  food  plant,  has  held  closely  to  it,  thus  avoiding  the  necessity  of 
seasonal  migration  5  and  that  in  northeastern  Ohio  and  possibly  in 
northern  Indiana  it  has  met  the  east-bound  tide  of  diffusion,  and  is 
perhaps  amalgamating  with  it.  (See  map,  fig.  17,  illustrating  supposed 
direction  of  diffusion  of  chinch  bug.) 

Although  not  at  all  conclusive  evidence,  I  might  add  that  the  single 
specimen  taken  at  Winnipeg  by  Dr.  Fletcher  was  of  the  macropterous 
form,  while  the  single  example  taken  by  Mr.  Van  Duzee  at  Muskoka, 
Canada,  was  of  the  brachypterous  form ;  and  this,  with  the  fact  that 
the  specimens  from  the  island  of  Granada  were  of  the  former  and  the 
Florida  coast  specimens  of  the  latter  exclusively,  shows  that  latitude 
and  climate  have  no  effect. 

HABITS  OF  THE  EUROPEAN  SPECIES  (BUSSUS  dori(B  Ferr.). 

Prompted  apparently  by  a  review  of  one  of  my  papers  read  before 
the  eight  annual  meeting  of  the  Association  of  Economic  Entomologists 
at  Buffalo,  in  1896,  Prof.  Karl  Sajo,  formerly  of  the  Kg.  Ung.  Staat- 
liche  Entomologische  Yersuchsstation,  at  Budapest,  published  in  the 
Illustr.  Wochenschrift  fur  Eutomologie,  Vol.  II,  pp.  449-451,  July  18, 
1897,  a  short  paper  on  "  Unser  BUssus  dorice,"  which  is  so  full  of  interest 
that  I  shall  beg  permission  to  present  it  here,  together  with  figures  of 
the  larval,  pupal,  and  adult  stages  of  the  insect  (Figs.  18  and  19). 

Professor  Sajo  writes  as  follows: 

In  the  article  on  the  eighth  annual  meeting  of  the  Association  of  Economic 
Entomologists  (Xo.  26,  pp.  401-403,  Illustr.  Wochenschrift  fiir  Entomologie),  the  very 
instructive  observations  of  Mr.  Webster  on  the  "  chinch  hug"  (BUssus  leucopterus) 
in  the  State  of  Ohio  were  discussed. 

In  view  of  this  communication  I  will  give  more  in  detail  that  which  I  have 
observed  concerning  our  European  species  of  this  genus,  namely,  BUssus  dorioe  Ferr. 

Like  the  North  American  larger  species,  the  smaller  European  one  appears  in 
two  forms,  namely,  the  wingless  and  the  winged.    The  first  describer  of  this  species, 


76 


THE  CHINCH  BUG. 


Fig.  18— Blissus  dorice:  a.  first nymph  j  c,  second:  b,  third; 
rf,  fourth.  (From  illustrations  prepared  in  the  Division 
of  Entomology.) 


Ferrari,  in  Genoa,  recognized  only  the  wingless  form,  which  with  its  aborted  wings 
looks  very  much  like  Heinipteron-nymphs,  and  probably  by  all  entomologists  who 
previously  saw  it  was  not  considered  as  a  sexually  developed  adult,  but  only  the 
immature  form  of  some  already  known  species.  I  discovered  the  winged  form  seven- 
teen years  ago(1880)in  the  steppes 
sand  desert,  called  "Nyires"  of 
the  Kis-Szent-Miklos,  and  de- 
scribed the  same.* 

I  at  that  time  made  known 
the  characters  of  the  immature 
forms,  which  can  not  be  confused 
with  the  individuals  which  have 
reached  complete  sexual  devel- 
opment, in  that  the  immature 
individuals  are  vermilion  red 
while  adult  individuals  are  dark 
browu.  It  is  interesting  that 
the  relationship  between  the 
winged  (macropterous)  and  the 
wingless  (brachypterous)  indi- 
viduals of  the  American  and  Eu- 
ropean species  is  very  different. 
For  while  in  America  those  individuals  which  reach  maturity  are  almost  always 
winged,  with  us  in  Europe  they  are  in  general  only  short-winged,  and  individuals 
capable  of  flight  are  not  observed;  and  the  fully  developed  macropterous  individ- 
uals were  not  thus  far,  according  to  my  knowledge,  found  in  any  other  place  than 
in  the  central  Hungarian  sand  dunes  already  named,  and  here  they  occurred  only 
on  a  single  little  portion  which  only  measured  a  few  paces  in  diameter.  It  was 
a  "Dunenhugel"  (sandy  hill)  covered  with  high,  scattered  poplars,  whose  fallen, 
dried  foliage  sparsely  covered  the  ground. 

Here  lived  the  colonies  o'f  Blissus  dorice  on  the  bases  of  the  bushy,  growing  grass, 
almost  under  the  surface  of  the 
ground,  and  well  concealed.  The 
habits  of  the  European  species  are 
also  in  the  main  similar  to  those  of 
her  American  relative,  since  the  latter 
also  lives  only  on  grasses,  and  during 
its  development  also  lives  very  close 
to  the  surface  of  the  ground. 

It  is  extremely  remarkable  that, 
even  though  B.  dorice  is  very  widely 
distributed  here,  and  is  met  with 
not  only  on  the  "Flugsande"  (sand 
drifts),  but  also  in  the  hilly  regions 
(e.  g.,  on  the  southern  exposure  of 
the  hill  which  stands  between  Duka 
and  Szod,  in  the  midst  of  bluffs  or 
rolling  hills),  the  winged  specimens 
were  to  be  found  only  on  the  very 

small  "Blissus  Island"  under  the  poplars.  But  here  also  they  were  found  but 
rarely,  and  only  then  when  the  transformation  from  the  pupa  to  adult  stage  was 
in  full  force.  "When  there  were  no  more  pnpse  to  be  fouud,  then  also  the  search  for 
lous-winged  individuals  was  in  vain. 


Fig.  19.— Blissus  dorice.  TTingless  form  at  left; 
w  inged  form  at  right.  (From  illustration  pre- 
pared in  the  Division  of  Entomology.) 


*K.  Sajo:  Die  bisher  unbekannte  makroptere  Form  von  Blissus  dorice  Ferr.  Ento- 
molog.  Nachrichten,  1880,  p.  235. 


HABITS  OF  THE  EUROPEAN  SPECIES. 


77 


This  .appearance  I  explain  in  this  way :  That  the  winged  examples,  as  soon  as  they 
were  able  to  fly,  quickly  Hew  away  and  disappeared  in  order  that  they  might  serve 
as  progenitors  for  new  colonies. 

But  the  place  of  discovery  has  since  been  transformed  into  an  immense  vineyard 
by  the  Government,  whereby  grass,  poplars,  and  also  B.  dorm  had  to  disappear 
from  thence.  For  four  years  I  have,  though  seeking  with  the  greatest  diligence, 
been  unable  to  get  track  of  the  winged  specimens  anywhere  in  this  region,  even 
though  I  know  of  a  number  of  colonies  of  this  species  upon  my  own  premises. 
While  formerly  I  captured  a  few  specimens  each  year  and  gave  them  partly  to 
museums  and  partly  to  entomologists,  I  scarcely  hope  to  attain  such  interesting  finds 
in  the  future. 

The  difference  just  mentioned  between  those  individuals  capable  of  flight  and 
those  not  capable  of  flight  in  our  species  aud  also  in  the  trans-Atlantic  species  can 
hardly  be  accidental,  but  may  be  sought  for  in  the  influences,  of  environment. 

Xext  there  crowds  to  the  front  the  fact  that  in  Xorth  America  B.  leucopterus  is 
continually  subjected  to  the  attack  of  its  deadly  fungus  parasite  to  a  high  degree, 
and  its  colonies  die  out  as  soon  as  rainy,  moist  atmosphere  prevails.  Consequently, 
the  Blissus  species  living  there  must  always  hunt  new  habitats  and  be  wandering 
continually  to  far  distant  localities.  For  this  wings  are  of  course  necessary,  and 
only  by  means  of  these  is  the  species  enabled  to  sustain  itself  at  such  a  high  grade 
of  importance  that  it  can,  now  here,  now  there,  become  a  veritable  plague  to 
agriculture. 

With  our  European  species  it  seems,  on  the  contrary,  in  regard  to  many  points  to 
be  otherwise;  for,  while  her  habits  in  the  main  are  similar  to  those  of  her  sister 
across  the  sea,  yet  there  are  found  many  important  differences  in  their  environment. 

Blissus  dor'm  never  congregates  in  such  close  masses  as  we  read  of  in  the  American 
reports.  It  forms  only  insect  islands,  and  even  individual  families  seem  to  scatter 
out  to  some  distance.  In  the  steppes,  moreover,  the  growth  of  grass  is  not  matted, 
but  stands  in  isolated  bunches  on  the  partially  bare  ground,  the  bunches  being  not 
infrequently  separated  by  several  paces. 

Our  species  will  not  go  into  cultivated  fields.  I  have  never  found  even  a  single 
specimen  among  forage  plants  that  have  been  sown,  and  already  this  condition  is 
one  of  the  reasons  why  the  European  species  does  not  cluster  together  in  such 
uninterrupted  masses. 

If,  then,  this  is  true  the  attacks  of  entomogenous  fungi  will  hardly  be  able  to 
create  such  havoc  in  B.  dorice  as  it  does  among  B.  leucopterus  in  America. 

I  have  also  during  eighteen  years  never  observed  a  wholesale  dying  off  in  the 
localities  of  occurrence  known  to  me.  The  fungus  S.  globuUferum  has  perhaps 
never  attacked  it,  and  even  though  the  European  form  were  susceptible  to  similar 
pestilences,  yet  it  is  always  hardly  to  be  doubted  that  the  fungus  in  the  European 
homes  of  B.  dorice  would  not  find  favorable  circumstances  in  that  here  during  the 
period  of  development  of  this  species  in  normal  years  great  drought  prevails.  Rains 
lasting  for  a  number  of  days,  with  continued  moist  and  warm  atmosphere  belong, 
with  us,  among  the  rarities,  especially  during  the  summer,  and  it  is  the  young  stages 
that  are  especially  sensitive  to  the  fungus  attack,  as  has  proven  to  be  the  case  in 
America. 

Among  insects  there  may  possibly  be  found  Blissus  enemies,  even  though  the 
extremely  penetrating  odor  of  this  bug,  which  is  identical  with  that  of  the  one  living 
in  beds  in  houses,  may  serve  as  a  protection. 

Taking  all  of  this  together,  we  observe  that  our  European  species  is  in  less  danger 
than  the  American,  and  that  it  is  not  subjected  to  catastrophes  of  total  destruction, 
so  far  as  has  yet  been  observable  in  the  stationary  localities  of  occurrence  in  the 
open  field,  for  I  have  never  yet  observed  a  sudden  disappearance  from  the  localities 
known  to  me.  It  is  not  necessary,  therefore,  for  it  to  be  continually  hunting  up 
new  fields  in  which  to  thrive,  and  there  was  no  apparent  reason  which  in  the 
struggle  for  existence  would  have  given  preponderance  to  the  long- winged  form; 


78 


THE  CHINCH  BUG. 


and  so  in  time,  in  the  generation  of  onr  species,  which  originally,  perhaps,  was  full 
winged,  the  winged  form  became  less  and  less  numerous,  until  to-day  we  see  almost 
entirely  hrachypterous  individuals  in  the  adult  stage,  exactly  the  same  as  in  the 
hedbug,  Acantkia  lectularia,  with  this  difference,  that  among  the  swarming  masses 
of  the  latter  nowadays  not  a  single  example  with  fully  developed  wings  can  he 
ound,  fortunately  for  us. 

It  is  evident  that  the  long-winged  tendency  in  B.  dor'uv  is  disappearing,  and  the 
time  may  come  when  one  will  he  unable  to  find  any  long-winged  specimens.  The 
designated  dangers,  on  the  contrary,  against  which  the  chinch  bug  must  fight  in 
North  America  require  very  strong  migratory  powers,  and,  consequently,  well- 
developed  wings,  through  which  this  especially  significant  difference  between 
B.  dor'uv  and  B.  Jeucoptcrus  has  been  brought  about. 

As  to  the  question  whether  or  not  our  species  shall  be  considered  injurious,  I  can 
answer  that  it  in  nowise  belongs  to  the  entirely  indifferent  insects,  but,  on  the  con- 
trary, contributes  to  the  complete  drying  up  of  the  rather  sparse  grasses  of  our 
steppe  meadows  during  the  summer.  But  since  it  has  not  thus  far  housed  in  the 
cultivated  fields,  it  can  not  be  placed  upon  the  black  list  of  serious  depredators. 
"Whether,  moreover,  in  the  future,  when  in  cousequence  of  the  continued  destruction 
of  its  herding  meadows,  its  original  food  plants  disappear  more  and  more,  B.  dor'uv 
may  become,  like  so  many  other  insect  species,  a  depredator  through  necessity  can 
only  be  conjectured.  We  have  in  this  regard  already  recorded  entirely  too  many 
remarkable  transformations  in  the  menu  of  other  species  to  disregard  entirely  the 
possibility  of  a  similar  transformation  in  the  life  habits  of  our  B.  dorm . 

I  wish  also  at  this  time  to  state,  for  the  benefit  of  our  many  readers  who  may  not 
be  familiar  with  it,  that  in  the  dimorphic  bugs,  especially  those  in  which  the  macrop- 
terous  and  brachypterous  forms  are  found  simultaneously,  the  former  possess  a  much 
stronger  and  broader  thorax  than  the  latter.  As  a  result  of  this  difference  in  their 
physical  structure,  one  is,  when  comparing  them  for  the  first  time,  easily  inclined  to 
designate  them  as  two  distinct  species. 

In  addition  to  this,  there  is  in  Blissus  the  strikingly  beautiful  coloration  of  the 
long-winged  specimens,  whose  clavus  and  corium  are  light  ocher-yellow,  and  the 
unusually  large  membrane,  which  is  about  twice  as  large  as  corium  and  clavus 
together,  and  of  an  entirely  milk-white  color,  making  the  long-winged  individuals 
very  prepossessing.  The  individuals  with  rudimentary  wings,  on  the  contrary,  are 
of  an  obscure  chocolate  brown.  The  larvae  are,  as  has  already  been  stated,  of  a 
bright  vermilion-red  color,  marked  with  black.  * 

With  the  foregoing  relative  to  the  habits  of  an  allied  species  of 
Blissus,  it  seems  to  me  that  we  can  the  better  understand  how,  under 
one  set  of  conditions,  all  traces  of  a  short-winged  form  might  entirely 
disappear,  while  with  another  set  of  conditions  this  tendency  might 
not  only  be  perpetuated,  but  greatly  emphasized.  The  two  species, 
B.  leucopterus  and  B.  doricv,  are  fully  illustrated  in  all  stages  of  devel- 
opment, as  well  as  both  macropterous  and  brachypterous  forms.  (See 
figs,  on  pp.  19,  20,  76).  For  specimens  of  the  latter  species,  B.  dorice, 
I  am  indebted  to  Professor  Sajo. 

PREVIOUS  IDEAS  ON  THE  DIFFUSION  OF  THE  CHINCH  BUG. 

Formerly,  it  was  supposed  that  the  chinch  bug  was  a  native  of  the 
Atlantic  coast  States,  and  that  it  made  its  way  westward  with  the 
advance  of  civilization  and  the  consequent  progress  of  wheat  growing. 


Translated  from  the  German  by  my  assistant,  Mr.  C.  W.  Mally. 


PREVIOUS  IDEAS  ON  THE  DIFFUSION. 


79 


This  theory  was  based  upon  the  fact  that  the  original  description  was 
drawn  up  from  a  specimen  from  the  eastern  shore  of  Virginia,  collected 
by  Mr.  Say  himself,*  and,  as  before  stated,  the  earliest  destruction  on 
record  caused  by  this  insect  occurred  in  ^North  Carolina,  and  they  also 
committed  great  depredations  in  Virginia  in  1839.  Up  to  this  time  it 
had  been  supposed  that  it  was  a  southern  species,  confined  to  the 
country  south  of  latitude  40°  north.  But  about  this  time  it  appeared 
in  Illinois,  at  iS"auvoo,  simultaneously  with  the  settlement  of  the  Mor- 
mons at  that  place,  and  as  many  supposed  that  this  sect  brought  them 
to  the  country  with  them,  they  were  locally  termed  u  Mormon  lice.*' 

In  his  second  report,  page  284,  Dr.  Fitch  states  that  Mr.  William 
Patten,  of  Sandwich,  Dekalb  County,  111.,  informed  him  that  the 
chinch  bug  first  appeared  in  that  locality  in  1850.  Mr.  Patten,  the 
father  of  Trof.  Simon  Patten,  now  of  the  University  of  Pennsylvania, 
and  the  writer's  father  settled  in  the  immediate  vicinity  of  Sandwich, 
111.,  in  1852.  This  was  ten  years  after  the  Pottawattamie  chief,  Shab- 
bona,  and  his  tribe  had  migrated  to  Kansas  or  Nebraska,  I  do  not 
remember  which,  but  do  recall  that  it  was  about  this  time  that  the 
prairie  fires  ceased  to  occur  over  any  wide  areas,  as  the  prairies  were 
no  longer  fired  annually  by  the  Indians.  The  whole  country  was  fast 
being  occupied,  and  I  well  remember  that  the  settlers  would  decide 
upon  a  certain  date  on  which  they  would  set  fire  to  the  wild  grass — in 
late  autumn — so  that  all  could  be  prepared.  I  may  also  state  that 
there  were  very  few  timothy  meadows  at  that  time,  as  the  wild  grass 
afforded  an  abundance  of  hay,  and  not  until  years  after  did  cultivated 
grasses  come  into  general  use.  The  writer  also  knows  from  personal 
experience  and  observation  that  with  the  decrease  in  prairie  fires  there 
came  an  increasing  abundance  of  chinch  bugs,  which  attacked  the 
wheat  fields  of  the  farmer,  t  This  was  in  a  country  where  there  was 
comparatively  little  timber,  the  only  forests,  if  such  they  could  be 
called,  being  along  the  streams  of  water.  I  am  confident  that  the 
chinch  bug  did  not  suddenly  make  its  appearance  in  that  section,  but 
that  with  the  increase  of  grain  growing  and  the  decrease  of  prairie 
fires  its  effects  began  to  be  more  and  more  marked.    Since  then  Prof. 

*  The  complete  writings  of  Thomas  Say,  edited  by  Le  Conte,  Vol.  I,  p.  329. 

t  Up  to  about  1862  these  fields  were  largely  of  spring  wheat,  but  about  that  time 
there  was  a  rapid  decline  in  the  growing  of  this  grain  in  northern  Illinois.  It  seems 
possible  that  spring  wheat  might  be  more  liable  to  attack  from  chinch  bugs  than 
fall  wheat,  as  the  former  is,  at  the  time  when  chinch  bugs  seek  out  their  breeding 
grounds,  more  tender  and  inviting  than  the  latter.  Mr.  Walter  Young,  writing  me 
from  Galesville,  Wis.,  states  that  his  spring  wheat  was  totally  destroyed  in  1897, 
though  there  had  been  none  sown  for  ten  years  previous  on  the  premises,  and  while 
the  chinch  bug  does  not  ordinarily  do  much  injury,  just  as  soon  as  spring  wheat  is 
sown  they  return,  as  it  were,  and  destroy  it. 

If  spring  wheat  is  so  attractive  to  chinch  bugs  in  spring  as  this  would  indicate, 
might  it  not  be  used  for  baits  instead  of  millet,  as  is  advised  further  on,  in  order  to 
draw  off  the  females  in  spring  when  seeking  localities  for  oviposition  ? 


80 


THE  CHINCH  BUG. 


S.  A.  Forbes  has  secured  in  tor  mat  ion  of  tbe  occurrence  of  these  insects 
in  sufficient  numbers  to  attract  attention  as  early  as  1823  in  southern 
Illinois,  and  within  25  miles  of  ^ew  Harmony,  Ind.,  where  Thomas 
Say  resided  and  did  the  most  of  his  entomological  work. 

REASONS  FOR  THE  PRESENT  THEORY  OF  DIFFUSION. 

It  seems  to  me  that  in  all  of  this  we  have  good  grounds  for  suppos- 
ing that  the  chinch  bug  occupied  the  most  of  the  country  prior  to  its 
occupancy  by  the  white  man,  and  that  its  first  depredations  were 
caused  by  its  own  advance  coming  in  contact  with  the  advance  of 
civilization;  and  the  simultaneous  cessation  of  forest  and  prairie  fires, 
with  the  displacement  of  the  native  grasses  by  large  areas  of  wheat, 
so  combined  that  the  points  of  contact  were  in  Illinois,  in  the  West, 
and  Virginia  and  North  Carolina  in  the  East.  Not  until  within  the 
last  fifteen  years  has  the  chinch  bug  been  known  to  work  serious  and 
widespread  injury  east  of  the  Allegheny  Mountains,  north  of  Virginia; 
and  west  of  these  mountains  they  have  done  scarcely  any  damage 
north  and  east  of  a  line  drawn  from  Chicago  southeast  to  Cincinnati. 
Thousands  of  farmers  in  Ohio  never  saw  a  chinch  bug  until  within  the 
last  four  years,  and  there  are  thousands  more  in  northwestern  Ohio, 
southern  Michigan,  and  northern  Indiana  that,  even  yet,  would  not  be 
able  to  recognize  one  were  they  to  see  it  among  their  growing  grain,  or 
even  if  in  abundance.  But  in  considering  this  matter  the  fact  must  be 
borne  in  mind  that  timothy  meadows  are  not  burned  over  annually  as 
were  the  forests  and  prairies,  and  the  stubble  does  not  die  with  the 
harvesting  of  the  crop  as  in  wheat,  and  therefore  does  not  necessitate 
annual  migrations  in  order  to  preserve  life.  In  a  timothy  meadow  the 
species  may  live  on  and  reproduce  year  after  year  without  ever  being 
obliged  to  abandon  the  field.  It  was  the  wheat  fields  of  the  West  that 
the  east-bound,  macropterous  tide  of  migration  found  confronting  it  in 
Illinois,  and  the  smaller  fields  of  grain  and  timothy  meadows  that  the 
combined  macropterous  and  brachypterous  forms,  more  or  less  maritime 
and  north-bound,  came  in  contact  with  along  the  Atlantic  coast,  while 
at  the  present  time  the  two  tides  of  migration  have  met  in  north- 
eastern Ohio  and  northern  Indiana. 

In  fig.  17  I  have  illustrated  the  theoretical  directions  and  courses 
taken  by  each  of  these  tides  of  migrations  from  the  tropical  regions, 
and  in  fig.  1  the  areas  over  which  the  species  is  now  known  to  occur 
in  Central  and  North  America  are  indicated. 

I  believe  that  this  same  course  of  migration  has  been  pursued,  at  least 
in  the  West,  by  the  several  species  of  Diabrotica,  and  especially  D. 
longicornis  Say,  and  to  a  less  extent  by  another  species  of  Hemiptera, 
Murgantia  Instrionica  Hahn.,  and  possibly  also  by  Dynastes  tity us  Linn., 
while  the  two  latter  with  others  are  now  working  northward  along  the 
Atlantic  coast.  Besides,  the  westward  tide  of  migration  has  been  fol- 
lowed in  all  probability  by  Pieris  rapes  Linn.,  Phytonomas  punctatus 


REASONS  FOR  PRESENT  THEORY  OF  DIFFUSION. 


81 


Fab.,  HylasUnus  trifolii  Mul.,  and  Grioceris  asparagi  Linn.,  all  of  which 
have  first  become  destructively  abundant  west  of  the  Allegheny  Moun- 
tains in  extreme  northeastern  Ohio.  The  last  four  species  having  been 
introduced  from  Europe,  there  is  no  doubt  as  to  their  migrating  west- 
ward. 

An  almost  total  lack  of  natural  enemies  in  the  United  States,  and 
with  nearly  all  of  its  closest  allies  belonging  in  Mexico  and  the  West 
Indies,  it  would  seem  as  though  we  were  in  possession  of  additional 
evidence  of  its  tropical  origin.  Besides  this  the  name  "  chinch  bug"  is 
of  Spanish  origin,  and  this  language  has  never  been  in  common  use  in 
North  America  except  in  Florida  and  the  country  along  the  Mexican 
border. 

The  species  certainly  prefers  the  low  country  to  the  higher,  and  is 
seldom  found  in  any  numbers  at  an  altitude  of  over  2,000  feet.  Gener- 
ally its  habitat  is  1,000  or  lower.  The  altitude  where  it  was  found 
breeding  on  Yolcan  de  Chiriqui,  in  Panama,  is  6,000  feet;  and  of  its  habi- 
tations in  Guatemala,  San  Geronimo,  is  3,000  feet;  Panzos,  2,000  feet; 
Champerico,  sea  level,  and  Bio  Naranjo,  about  2,000  feet,  while  in  Colo- 
rado it  occurs  sparingly  near  Fort  Collins  at  an  elevation  of  5,500  to 
6,000  feet,  while  Professor  Cockerell  did  not  find  it  at  all  in  the  same 
State  at  elevations  of  7,000  to  8,000  feet.  On  Mount  Washington,  in 
New  Hampshire,  it  has  been  found  only  once,  and  this  time  by  Dr. 
Packard,  on  the  summit,  which  has  an  elevation  of  6,500  feet.* 

In  my  own  experience,  running  over  something  like  forty  years,  I 
have  never  witnessed  serious  injury  to  crops  on  hilly  land  by  chinch 
bugs.  It  may  be  stated,  however,  that  all  of  my  studies  of  the  insect 
have  been  carried  on  in  a  level  country,  Ohio  being  the  most  uneven 
and  hilly,  but  even  here  all  of  the  outbreaks  that  I  have  observed  were 
on  level  areas.  In  Minnesota,  however,  Dr.  Lugger  has  found  that 
those  grain  fields  which  are  most  seriously  injured  are  located  near  the 
edges  of  woods  or  on  slopes.  In  some  published  observations  of  Pro- 
fessor Osborn,  in  Iowa,  kindly  placed  at  my  disposal  by  Dr.  Howard, 
I  find  that  in  1894,  about  90  per  cent  of  the  infested  fields  examined  by 
Professor  Osborn  were  on  high  ground  and  about  80  per  cent  of  the 
fields  were  hilly  and  ridges,  in  most  cases  the  damage  being  first  appar- 
ent upon  the  higher  portions  of  the  fields.  The  exceptions  were  where 
the  chinch  bug  had  evidently  hibernated  in  wild  grass  and  weeds  occur- 
ring in  the  lower  places,  and  these  had  been  very  dry  for  the  twelve 
months  preceding  the  damage  of  that  year.  Besides,  both  the  Iowa 
and  Minnesota  areas  are  below  1,000  feet  elevation. 

The  area  over  which  the  chinch  bug  is  more  especially  abundant  and 
destructive  comprises  such  a  variety  of  soils  and  geological  formations 
that  a  study  of  these  factors  at  once  shows  that  neither  has  any  mate- 
rial influence  in  the  distribution  of  the  species,  at  least  in  the  United 

*  See  my  paper  on  Origin  and  Diffusion  of  Blissits  leucopterus  and  Murgantia  histri- 
on  ica,  in  Journal  of  Cincinnati  Society  of  Natural  History,  Vol.  XVIII,  February,  1896. 

5968— No.  15  6 


82 


THE  CHINCH  BUG. 


States.  In  its  northernmost  habitat  it  would  not  be  at  all  surprising 
that  it  should  prefer  a  sandy,  rather  than  a  clay,  soil,  the  former  being- 
looser  and  warmer  on  or  near  the  surface.    (See  fig.  G.) 

In  conclusion,  then,  on  this  point  it  may  be  stated  that  if  JUissus 
leucopterus  originated  in  the  Western  Hemisphere  it  was  probably  near 
the  tropics,  and  it  is  not  impossible  that  its  generic  ancestors  may  have 
been  carried  from  Europe  or  Africa  by  either  the  north  equatorial  or 
the  main  equatorial  Atlantic  currents,  landing  them  on  the  northern 
shores  of  South  America  or  on  some  closely  located  islands,  from  which 
the  species  has  spread  coastwise  around  the  Caribbean  Sea  and  the 
Gulf  of  Mexico,  as  previously  indicated.  In  this  connection  it  is  inter- 
esting to  note  that  specimens  from  Grenada,  collected  on  the  Mount 
Joy  and  Caliveny  estates  by  Mr.  H.  H.  Smith  in  June  and  September, 
show  that  the  species  here  attains  a  large  size  and  is  more  variable, 
both  in  size  and  markings,  than  is  commonly  found  to  be  the  case  in 
the  eastern  United  States.* 


*  Uliler  on  Hemiptera-Heteroptera  from  St.  Vincent  and  Grenada,  Proc.  Zool.  Soc., 
London,  1894. 

O 


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